aboutsummaryrefslogtreecommitdiffstats
path: root/plugins/mod_bosh.lua
blob: a6b84367a392703956f2886d6589f1f2a944682d (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
-- 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.host = "*" -- Global module

local hosts = _G.hosts;
local lxp = require "lxp";
local new_xmpp_stream = require "util.xmppstream".new;
local httpserver = require "net.httpserver";
local sm = require "core.sessionmanager";
local sm_destroy_session = sm.destroy_session;
local new_uuid = require "util.uuid".generate;
local fire_event = prosody.events.fire_event;
local core_process_stanza = core_process_stanza;
local st = require "util.stanza";
local logger = require "util.logger";
local log = logger.init("mod_bosh");
local timer = require "util.timer";

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" };

local BOSH_DEFAULT_HOLD = tonumber(module:get_option("bosh_default_hold")) or 1;
local BOSH_DEFAULT_INACTIVITY = tonumber(module:get_option("bosh_max_inactivity")) or 60;
local BOSH_DEFAULT_POLLING = tonumber(module:get_option("bosh_max_polling")) or 5;
local BOSH_DEFAULT_REQUESTS = tonumber(module:get_option("bosh_max_requests")) or 2;

local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");

local default_headers = { ["Content-Type"] = "text/xml; charset=utf-8" };

local cross_domain = module:get_option("cross_domain_bosh");
if cross_domain then
	default_headers["Access-Control-Allow-Methods"] = "GET, POST, OPTIONS";
	default_headers["Access-Control-Allow-Headers"] = "Content-Type";
	default_headers["Access-Control-Max-Age"] = "7200";

	if cross_domain == true then
		default_headers["Access-Control-Allow-Origin"] = "*";
	elseif type(cross_domain) == "table" then
		cross_domain = table.concat(cross_domain, ", ");
	end
	if type(cross_domain) == "string" then
		default_headers["Access-Control-Allow-Origin"] = cross_domain;
	end
end

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

local function get_ip_from_request(request)
	local ip = request.handler: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;
local os_time = os.time;

local sessions = {};
local inactive_sessions = {}; -- Sessions which have no open requests

-- Used to respond to idle sessions (those with waiting requests)
local waiting_requests = {};
function on_destroy_request(request)
	waiting_requests[request] = nil;
	local session = sessions[request.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
		if #requests == 0 and session.bosh_max_inactive and not inactive_sessions[session] then
			inactive_sessions[session] = os_time();
			(session.log or log)("debug", "BOSH session marked as inactive at %d", inactive_sessions[session]);
		end
	end
end

function handle_request(method, body, request)
	if (not body) or request.method ~= "POST" then
		if request.method == "OPTIONS" then
			local headers = {};
			for k,v in pairs(default_headers) do headers[k] = v; end
			headers["Content-Type"] = nil;
			return { headers = headers, body = "" };
		else
			return "<html><body>You really don't look like a BOSH client to me... what do you want?</body></html>";
		end
	end
	if not method then
		log("debug", "Request %s suffered error %s", tostring(request.id), body);
		return;
	end
	--log("debug", "Handling new request %s: %s\n----------", request.id, tostring(body));
	request.notopen = true;
	request.log = log;
	request.on_destroy = on_destroy_request;
	
	local stream = new_xmpp_stream(request, stream_callbacks);
	-- stream:feed() calls the stream_callbacks, so all stanzas in
	-- the body are processed in this next line before it returns.
	stream:feed(body);
	
	local session = sessions[request.sid];
	if session then
		-- Session was marked as inactive, since we have
		-- a request open now, unmark it
		if inactive_sessions[session] and #session.requests > 0 then
			inactive_sessions[session] = nil;
		end

		local r = session.requests;
		log("debug", "Session %s has %d out of %d requests open", request.sid, #r, session.bosh_hold);
		log("debug", "and there are %d things in the send_buffer", #session.send_buffer);
		if #r > session.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 request.destroyed then
			-- We're keeping this request open, to respond later
			log("debug", "Have nothing to say, so leaving request unanswered for now");
			if session.bosh_wait then
				request.reply_before = os_time() + session.bosh_wait;
				waiting_requests[request] = true;
			end
		end
		
		if session.bosh_terminate then
			session.log("debug", "Closing session with %d requests open", #session.requests);
			session:close();
			return nil;
		else
			return true; -- Inform httpserver we shall reply later
		end
	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:streams"] = 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 session_close_response = { headers = default_headers, body = tostring(close_reply) };

	for _, held_request in ipairs(session.requests) do
		held_request:send(session_close_response);
		held_request:destroy();
	end
	sessions[session.sid]  = nil;
	sm_destroy_session(session);
end

function stream_callbacks.streamopened(request, attr)
	log("debug", "BOSH body open (sid: %s)", attr.sid);
	local sid = attr.sid
	if not sid then
		-- New session request
		request.notopen = nil; -- Signals that we accept this opening tag
		
		-- TODO: Sanity checks here (rid, to, known host, etc.)
		if not hosts[attr.to] 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:streams"] = xmlns_streams, condition = "host-unknown" });
			request:send(tostring(close_reply));
			return;
		end
		
		-- New session
		sid = new_uuid();
		local session = {
			type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid), host = attr.to,
			bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
			bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
			requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
			close = bosh_close_stream, dispatch_stanza = core_process_stanza,
			log = logger.init("bosh"..sid),	secure = consider_bosh_secure or request.secure,
			ip = get_ip_from_request(request);
		};
		sessions[sid] = session;
		
		session.log("debug", "BOSH session created for request from %s", session.ip);
		log("info", "New BOSH session, assigned it sid '%s'", sid);
		local r, send_buffer = session.requests, session.send_buffer;
		local response = { headers = default_headers }
		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
			--log("debug", "Sending BOSH data: %s", tostring(s));
			local oldest_request = r[1];
			if oldest_request then
				log("debug", "We have an open request, so sending on that");
				response.body = t_concat({
					"<body xmlns='http://jabber.org/protocol/httpbind' ",
					session.bosh_terminate and "type='terminate' " or "",
					"sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>",
					tostring(s),
					"</body>"
				});
				oldest_request:send(response);
				--log("debug", "Sent");
				if oldest_request.stayopen then
					if #r>1 then
						-- Move front request to back
						t_insert(r, oldest_request);
						t_remove(r, 1);
					end
				else
					log("debug", "Destroying the request now...");
					oldest_request:destroy();
				end
			elseif s ~= "" then
				log("debug", "Saved to send buffer because there are %d open requests", #r);
				-- Hmm, no requests are open :(
				t_insert(session.send_buffer, tostring(s));
				log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
			end
			return true;
		end
		
		-- Send creation response
		
		local features = st.stanza("stream:features");
		hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
		fire_event("stream-features", session, features);
		--xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
		local response = st.stanza("body", { xmlns = xmlns_bosh,
			wait = attr.wait,
			inactivity = tostring(BOSH_DEFAULT_INACTIVITY),
			polling = tostring(BOSH_DEFAULT_POLLING),
			requests = tostring(BOSH_DEFAULT_REQUESTS),
			hold = tostring(session.bosh_hold),
			sid = sid, authid = sid,
			ver  = '1.6', from = session.host,
			secure = 'true', ["xmpp:version"] = "1.0",
			["xmlns:xmpp"] = "urn:xmpp:xbosh",
			["xmlns:stream"] = "http://etherx.jabber.org/streams"
		}):add_child(features);
		request:send{ headers = default_headers, body = tostring(response) };
		
		request.sid = sid;
		return;
	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);
		request:send{ headers = default_headers, body = tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })) };
		request.notopen = nil;
		return;
	end
	
	if session.rid then
		local rid = tonumber(attr.rid);
		local diff = rid - session.rid;
		if diff > 1 then
			session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
		elseif diff <= 0 then
			-- Repeated, ignore
			session.log("debug", "rid repeated (on request %s), ignoring: %s (diff %d)", request.id, session.rid, diff);
			request.notopen = nil;
			request.ignore = true;
			request.sid = sid;
			t_insert(session.requests, request);
			return;
		end
		session.rid = rid;
	end
	
	if session.notopen then
		local features = st.stanza("stream:features");
		hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
		fire_event("stream-features", session, features);
		session.send(features);
		session.notopen = nil;
	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

	request.notopen = nil; -- Signals that we accept this opening tag
	t_insert(session.requests, request);
	request.sid = sid;
end

function stream_callbacks.handlestanza(request, stanza)
	if request.ignore then return; end
	log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
	local session = sessions[request.sid];
	if session then
		if stanza.attr.xmlns == xmlns_bosh then
			stanza.attr.xmlns = nil;
		end
		core_process_stanza(session, stanza);
	end
end

function stream_callbacks.error(request, error)
	log("debug", "Error parsing BOSH request payload; %s", error);
	if not request.sid then
		request:send({ headers = default_headers, status = "400 Bad Request" });
		return;
	end
	
	local session = sessions[request.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 dead_sessions = {};
function on_timer()
	-- log("debug", "Checking for requests soon to timeout...");
	-- Identify requests timing out within the next few seconds
	local now = os_time() + 3;
	for request in pairs(waiting_requests) do
		if request.reply_before <= now then
			log("debug", "%s was soon to timeout, sending empty response", request.id);
			-- Send empty response to let the
			-- client know we're still here
			if request.conn then
				sessions[request.sid].send("");
			end
		end
	end
	
	now = now - 3;
	local n_dead_sessions = 0;
	for session, inactive_since in pairs(inactive_sessions) do
		if session.bosh_max_inactive then
			if now - inactive_since > session.bosh_max_inactive then
				(session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
				sessions[session.sid]  = nil;
				inactive_sessions[session] = nil;
				n_dead_sessions = n_dead_sessions + 1;
				dead_sessions[n_dead_sessions] = session;
			end
		else
			inactive_sessions[session] = nil;
		end
	end

	for i=1,n_dead_sessions do
		local session = dead_sessions[i];
		dead_sessions[i] = nil;
		sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
	end
	return 1;
end


local function setup()
	local ports = module:get_option("bosh_ports") or { 5280 };
	httpserver.new_from_config(ports, handle_request, { base = "http-bind" });
	timer.add_task(1, on_timer);
end
if prosody.start_time then -- already started
	setup();
else
	prosody.events.add_handler("server-started", setup);
end