prosody
474684c07a3a
plugins/mod_s2s/s2sout.lib.lua

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plugins/mod_s2s/s2sout.lib.lua @ 4814:474684c07a3a

Rename plugins/s2s/ to plugins/mod_s2s/
author Matthew Wild <mwild1@gmail.com>
date Fri, 04 May 2012 00:05:15 +0100
parent 4791:plugins/s2s/s2sout.lib.lua@c01066f27a5d
child 4832:6b3aec1e0d9f
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equal deleted inserted replaced
4813:77da9671ac39 4814:474684c07a3a
1 -- Prosody IM
2 -- Copyright (C) 2008-2010 Matthew Wild
3 -- Copyright (C) 2008-2010 Waqas Hussain
4 --
5 -- This project is MIT/X11 licensed. Please see the
6 -- COPYING file in the source package for more information.
7 --
8
9 --- Module containing all the logic for connecting to a remote server
10
11 local portmanager = require "core.portmanager";
12 local wrapclient = require "net.server".wrapclient;
13 local initialize_filters = require "util.filters".initialize;
14 local idna_to_ascii = require "util.encodings".idna.to_ascii;
15 local new_ip = require "util.ip".new_ip;
16 local rfc3484_dest = require "util.rfc3484".destination;
17 local socket = require "socket";
18 local adns = require "net.adns";
19 local dns = require "net.dns";
20 local t_insert, t_sort, ipairs = table.insert, table.sort, ipairs;
21 local st = require "util.stanza";
22
23 local s2s_destroy_session = require "core.s2smanager".destroy_session;
24
25 local log = module._log;
26
27 local sources = {};
28
29 local max_dns_depth = module:get_option_number("dns_max_depth", 3);
30
31 local s2sout = {};
32
33 local s2s_listener;
34
35
36 function s2sout.set_listener(listener)
37 s2s_listener = listener;
38 end
39
40 local function compare_srv_priorities(a,b)
41 return a.priority < b.priority or (a.priority == b.priority and a.weight > b.weight);
42 end
43
44 local function session_open_stream(session, from, to)
45 session.sends2s(st.stanza("stream:stream", {
46 xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
47 ["xmlns:stream"]='http://etherx.jabber.org/streams',
48 from=from, to=to, version='1.0', ["xml:lang"]='en'}):top_tag());
49 end
50
51 function s2sout.initiate_connection(host_session)
52 initialize_filters(host_session);
53 host_session.open_stream = session_open_stream;
54
55 -- Kick the connection attempting machine into life
56 if not s2sout.attempt_connection(host_session) then
57 -- Intentionally not returning here, the
58 -- session is needed, connected or not
59 s2s_destroy_session(host_session);
60 end
61
62 if not host_session.sends2s then
63 -- A sends2s which buffers data (until the stream is opened)
64 -- note that data in this buffer will be sent before the stream is authed
65 -- and will not be ack'd in any way, successful or otherwise
66 local buffer;
67 function host_session.sends2s(data)
68 if not buffer then
69 buffer = {};
70 host_session.send_buffer = buffer;
71 end
72 log("debug", "Buffering data on unconnected s2sout to %s", tostring(host_session.to_host));
73 buffer[#buffer+1] = data;
74 log("debug", "Buffered item %d: %s", #buffer, tostring(data));
75 end
76 end
77 end
78
79 function s2sout.attempt_connection(host_session, err)
80 local from_host, to_host = host_session.from_host, host_session.to_host;
81 local connect_host, connect_port = to_host and idna_to_ascii(to_host), 5269;
82
83 if not connect_host then
84 return false;
85 end
86
87 if not err then -- This is our first attempt
88 log("debug", "First attempt to connect to %s, starting with SRV lookup...", to_host);
89 host_session.connecting = true;
90 local handle;
91 handle = adns.lookup(function (answer)
92 handle = nil;
93 host_session.connecting = nil;
94 if answer then
95 log("debug", to_host.." has SRV records, handling...");
96 local srv_hosts = {};
97 host_session.srv_hosts = srv_hosts;
98 for _, record in ipairs(answer) do
99 t_insert(srv_hosts, record.srv);
100 end
101 if #srv_hosts == 1 and srv_hosts[1].target == "." then
102 log("debug", to_host.." does not provide a XMPP service");
103 s2s_destroy_session(host_session, err); -- Nothing to see here
104 return;
105 end
106 t_sort(srv_hosts, compare_srv_priorities);
107
108 local srv_choice = srv_hosts[1];
109 host_session.srv_choice = 1;
110 if srv_choice then
111 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
112 log("debug", "Best record found, will connect to %s:%d", connect_host, connect_port);
113 end
114 else
115 log("debug", to_host.." has no SRV records, falling back to A");
116 end
117 -- Try with SRV, or just the plain hostname if no SRV
118 local ok, err = s2sout.try_connect(host_session, connect_host, connect_port);
119 if not ok then
120 if not s2sout.attempt_connection(host_session, err) then
121 -- No more attempts will be made
122 s2s_destroy_session(host_session, err);
123 end
124 end
125 end, "_xmpp-server._tcp."..connect_host..".", "SRV");
126
127 return true; -- Attempt in progress
128 elseif host_session.ip_hosts then
129 return s2sout.try_connect(host_session, connect_host, connect_port, err);
130 elseif host_session.srv_hosts and #host_session.srv_hosts > host_session.srv_choice then -- Not our first attempt, and we also have SRV
131 host_session.srv_choice = host_session.srv_choice + 1;
132 local srv_choice = host_session.srv_hosts[host_session.srv_choice];
133 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
134 host_session.log("info", "Connection failed (%s). Attempt #%d: This time to %s:%d", tostring(err), host_session.srv_choice, connect_host, connect_port);
135 else
136 host_session.log("info", "Out of connection options, can't connect to %s", tostring(host_session.to_host));
137 -- We're out of options
138 return false;
139 end
140
141 if not (connect_host and connect_port) then
142 -- Likely we couldn't resolve DNS
143 log("warn", "Hmm, we're without a host (%s) and port (%s) to connect to for %s, giving up :(", tostring(connect_host), tostring(connect_port), tostring(to_host));
144 return false;
145 end
146
147 return s2sout.try_connect(host_session, connect_host, connect_port);
148 end
149
150 function s2sout.try_next_ip(host_session)
151 host_session.connecting = nil;
152 host_session.ip_choice = host_session.ip_choice + 1;
153 local ip = host_session.ip_hosts[host_session.ip_choice];
154 local ok, err= s2sout.make_connect(host_session, ip.ip, ip.port);
155 if not ok then
156 if not s2sout.attempt_connection(host_session, err or "closed") then
157 err = err and (": "..err) or "";
158 s2s_destroy_session(host_session, "Connection failed"..err);
159 end
160 end
161 end
162
163 function s2sout.try_connect(host_session, connect_host, connect_port, err)
164 host_session.connecting = true;
165
166 if not err then
167 local IPs = {};
168 host_session.ip_hosts = IPs;
169 local handle4, handle6;
170 local has_other = false;
171
172 handle4 = adns.lookup(function (reply, err)
173 handle4 = nil;
174
175 -- COMPAT: This is a compromise for all you CNAME-(ab)users :)
176 if not (reply and reply[#reply] and reply[#reply].a) then
177 local count = max_dns_depth;
178 reply = dns.peek(connect_host, "CNAME", "IN");
179 while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do
180 log("debug", "Looking up %s (DNS depth is %d)", tostring(reply[#reply].cname), count);
181 reply = dns.peek(reply[#reply].cname, "A", "IN") or dns.peek(reply[#reply].cname, "CNAME", "IN");
182 count = count - 1;
183 end
184 end
185 -- end of CNAME resolving
186
187 if reply and reply[#reply] and reply[#reply].a then
188 for _, ip in ipairs(reply) do
189 log("debug", "DNS reply for %s gives us %s", connect_host, ip.a);
190 IPs[#IPs+1] = new_ip(ip.a, "IPv4");
191 end
192 end
193
194 if has_other then
195 if #IPs > 0 then
196 rfc3484_dest(host_session.ip_hosts, sources);
197 for i = 1, #IPs do
198 IPs[i] = {ip = IPs[i], port = connect_port};
199 end
200 host_session.ip_choice = 0;
201 s2sout.try_next_ip(host_session);
202 else
203 log("debug", "DNS lookup failed to get a response for %s", connect_host);
204 host_session.ip_hosts = nil;
205 if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can
206 log("debug", "No other records to try for %s - destroying", host_session.to_host);
207 err = err and (": "..err) or "";
208 s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
209 end
210 end
211 else
212 has_other = true;
213 end
214 end, connect_host, "A", "IN");
215
216 handle6 = adns.lookup(function (reply, err)
217 handle6 = nil;
218
219 if reply and reply[#reply] and reply[#reply].aaaa then
220 for _, ip in ipairs(reply) do
221 log("debug", "DNS reply for %s gives us %s", connect_host, ip.aaaa);
222 IPs[#IPs+1] = new_ip(ip.aaaa, "IPv6");
223 end
224 end
225
226 if has_other then
227 if #IPs > 0 then
228 rfc3484_dest(host_session.ip_hosts, sources);
229 for i = 1, #IPs do
230 IPs[i] = {ip = IPs[i], port = connect_port};
231 end
232 host_session.ip_choice = 0;
233 s2sout.try_next_ip(host_session);
234 else
235 log("debug", "DNS lookup failed to get a response for %s", connect_host);
236 host_session.ip_hosts = nil;
237 if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can
238 log("debug", "No other records to try for %s - destroying", host_session.to_host);
239 err = err and (": "..err) or "";
240 s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
241 end
242 end
243 else
244 has_other = true;
245 end
246 end, connect_host, "AAAA", "IN");
247
248 return true;
249 elseif host_session.ip_hosts and #host_session.ip_hosts > host_session.ip_choice then -- Not our first attempt, and we also have IPs left to try
250 s2sout.try_next_ip(host_session);
251 else
252 host_session.ip_hosts = nil;
253 if not s2sout.attempt_connection(host_session, "out of IP addresses") then -- Retry if we can
254 log("debug", "No other records to try for %s - destroying", host_session.to_host);
255 err = err and (": "..err) or "";
256 s2s_destroy_session(host_session, "Connecting failed"..err); -- End of the line, we can't
257 return false;
258 end
259 end
260
261 return true;
262 end
263
264 function s2sout.make_connect(host_session, connect_host, connect_port)
265 (host_session.log or log)("info", "Beginning new connection attempt to %s ([%s]:%d)", host_session.to_host, connect_host.addr, connect_port);
266 -- Ok, we're going to try to connect
267
268 local from_host, to_host = host_session.from_host, host_session.to_host;
269
270 local conn, handler;
271 if connect_host.proto == "IPv4" then
272 conn, handler = socket.tcp();
273 else
274 if not socket.tcp6 then
275 log("warn", "Could not connect to "..to_host..". Your version of lua-socket does not support IPv6");
276 return false, "no-ipv6";
277 end
278 conn, handler = socket.tcp6();
279 end
280
281 if not conn then
282 log("warn", "Failed to create outgoing connection, system error: %s", handler);
283 return false, handler;
284 end
285
286 conn:settimeout(0);
287 local success, err = conn:connect(connect_host.addr, connect_port);
288 if not success and err ~= "timeout" then
289 log("warn", "s2s connect() to %s (%s:%d) failed: %s", host_session.to_host, connect_host.addr, connect_port, err);
290 return false, err;
291 end
292
293 conn = wrapclient(conn, connect_host.addr, connect_port, s2s_listener, "*a");
294 host_session.conn = conn;
295
296 local filter = initialize_filters(host_session);
297 local w, log = conn.write, host_session.log;
298 host_session.sends2s = function (t)
299 log("debug", "sending: %s", (t.top_tag and t:top_tag()) or t:match("^[^>]*>?"));
300 if t.name then
301 t = filter("stanzas/out", t);
302 end
303 if t then
304 t = filter("bytes/out", tostring(t));
305 if t then
306 return w(conn, tostring(t));
307 end
308 end
309 end
310
311 -- Register this outgoing connection so that xmppserver_listener knows about it
312 -- otherwise it will assume it is a new incoming connection
313 s2s_listener.register_outgoing(conn, host_session);
314
315 host_session:open_stream(from_host, to_host);
316
317 log("debug", "Connection attempt in progress...");
318 return true;
319 end
320
321 module:hook_global("service-added", function (event)
322 if event.name ~= "s2s" then return end
323
324 local s2s_sources = portmanager.get_active_services():get("s2s");
325 if not s2s_sources then
326 module:log("warn", "s2s not listening on any ports, outgoing connections may fail");
327 return;
328 end
329 for source, _ in pairs(s2s_sources) do
330 if source == "*" or source == "0.0.0.0" then
331 if not socket.local_addresses then
332 sources[#sources + 1] = new_ip("0.0.0.0", "IPv4");
333 else
334 for _, addr in ipairs(socket.local_addresses("ipv4", true)) do
335 sources[#sources + 1] = new_ip(addr, "IPv4");
336 end
337 end
338 elseif source == "::" then
339 if not socket.local_addresses then
340 sources[#sources + 1] = new_ip("::", "IPv6");
341 else
342 for _, addr in ipairs(socket.local_addresses("ipv6", true)) do
343 sources[#sources + 1] = new_ip(addr, "IPv6");
344 end
345 end
346 else
347 sources[#sources + 1] = new_ip(source, (source:find(":") and "IPv6") or "IPv4");
348 end
349 end
350 end);
351
352 return s2sout;