prosody
3dce04129693
plugins/s2s/s2sout.lib.lua

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plugins/s2s/s2sout.lib.lua @ 4555:3dce04129693

s2smanager, mod_s2s, mod_s2s/s2sout: Split connection handling out of s2smanager into mod_s2s, and further split connection logic for s2sout to a module lib, s2sout.lib.lua
author Matthew Wild <mwild1@gmail.com>
date Mon, 23 Jan 2012 16:28:20 +0000
child 4562:b163c65379a4
child 4569:34b1122126f6
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equal deleted inserted replaced
4554:6ceabde7af91 4555:3dce04129693
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 initialize_filters = require "util.filters".initialize;
12 local idna_to_ascii = require "util.encodings".idna.to_ascii;
13 local add_task = require "util.timer".add_task;
14 local socket = require "socket";
15
16 local s2s_destroy_session = require "core.s2smanager".destroy_session;
17
18 local s2sout = {};
19
20 local s2s_listener;
21
22 function s2sout.set_listener(listener)
23 s2s_listener = listener;
24 end
25
26 local function compare_srv_priorities(a,b)
27 return a.priority < b.priority or (a.priority == b.priority and a.weight > b.weight);
28 end
29
30 local function session_open_stream(session, from, to)
31 session.sends2s(st.stanza("stream:stream", {
32 xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
33 ["xmlns:stream"]='http://etherx.jabber.org/streams',
34 from=from, to=to, version='1.0', ["xml:lang"]='en'}):top_tag());
35 end
36
37 function s2sout.initiate_connection(host_session)
38 initialize_filters(host_session);
39 session.open_stream = session_open_stream;
40
41 -- Kick the connection attempting machine into life
42 if not s2sout.attempt_connection(host_session) then
43 -- Intentionally not returning here, the
44 -- session is needed, connected or not
45 s2s_destroy_session(host_session);
46 end
47
48 if not host_session.sends2s then
49 -- A sends2s which buffers data (until the stream is opened)
50 -- note that data in this buffer will be sent before the stream is authed
51 -- and will not be ack'd in any way, successful or otherwise
52 local buffer;
53 function host_session.sends2s(data)
54 if not buffer then
55 buffer = {};
56 host_session.send_buffer = buffer;
57 end
58 log("debug", "Buffering data on unconnected s2sout to %s", to_host);
59 buffer[#buffer+1] = data;
60 log("debug", "Buffered item %d: %s", #buffer, tostring(data));
61 end
62 end
63 end
64
65 function s2sout.attempt_connection(host_session, err)
66 local from_host, to_host = host_session.from_host, host_session.to_host;
67 local connect_host, connect_port = to_host and idna_to_ascii(to_host), 5269;
68
69 if not connect_host then
70 return false;
71 end
72
73 if not err then -- This is our first attempt
74 log("debug", "First attempt to connect to %s, starting with SRV lookup...", to_host);
75 host_session.connecting = true;
76 local handle;
77 handle = adns.lookup(function (answer)
78 handle = nil;
79 host_session.connecting = nil;
80 if answer then
81 log("debug", to_host.." has SRV records, handling...");
82 local srv_hosts = {};
83 host_session.srv_hosts = srv_hosts;
84 for _, record in ipairs(answer) do
85 t_insert(srv_hosts, record.srv);
86 end
87 if #srv_hosts == 1 and srv_hosts[1].target == "." then
88 log("debug", to_host.." does not provide a XMPP service");
89 s2s_destroy_session(host_session, err); -- Nothing to see here
90 return;
91 end
92 t_sort(srv_hosts, compare_srv_priorities);
93
94 local srv_choice = srv_hosts[1];
95 host_session.srv_choice = 1;
96 if srv_choice then
97 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
98 log("debug", "Best record found, will connect to %s:%d", connect_host, connect_port);
99 end
100 else
101 log("debug", to_host.." has no SRV records, falling back to A");
102 end
103 -- Try with SRV, or just the plain hostname if no SRV
104 local ok, err = s2sout.try_connect(host_session, connect_host, connect_port);
105 if not ok then
106 if not s2sout.attempt_connection(host_session, err) then
107 -- No more attempts will be made
108 s2s_destroy_session(host_session, err);
109 end
110 end
111 end, "_xmpp-server._tcp."..connect_host..".", "SRV");
112
113 return true; -- Attempt in progress
114 elseif host_session.ip_hosts then
115 return s2sout.try_connect(host_session, connect_host, connect_port, err);
116 elseif host_session.srv_hosts and #host_session.srv_hosts > host_session.srv_choice then -- Not our first attempt, and we also have SRV
117 host_session.srv_choice = host_session.srv_choice + 1;
118 local srv_choice = host_session.srv_hosts[host_session.srv_choice];
119 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
120 host_session.log("info", "Connection failed (%s). Attempt #%d: This time to %s:%d", tostring(err), host_session.srv_choice, connect_host, connect_port);
121 else
122 host_session.log("info", "Out of connection options, can't connect to %s", tostring(host_session.to_host));
123 -- We're out of options
124 return false;
125 end
126
127 if not (connect_host and connect_port) then
128 -- Likely we couldn't resolve DNS
129 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));
130 return false;
131 end
132
133 return s2sout.try_connect(host_session, connect_host, connect_port);
134 end
135
136 function s2sout.try_next_ip(host_session)
137 host_session.connecting = nil;
138 host_session.ip_choice = host_session.ip_choice + 1;
139 local ip = host_session.ip_hosts[host_session.ip_choice];
140 local ok, err= s2sout.make_connect(host_session, ip.ip, ip.port);
141 if not ok then
142 if not s2sout.attempt_connection(host_session, err or "closed") then
143 err = err and (": "..err) or "";
144 s2s_destroy_session(host_session, "Connection failed"..err);
145 end
146 end
147 end
148
149 function s2sout.try_connect(host_session, connect_host, connect_port, err)
150 host_session.connecting = true;
151
152 if not err then
153 local IPs = {};
154 host_session.ip_hosts = IPs;
155 local handle4, handle6;
156 local has_other = false;
157
158 if not sources then
159 sources = {};
160 for i, source in ipairs(cfg_sources) do
161 if source == "*" then
162 sources[i] = new_ip("0.0.0.0", "IPv4");
163 else
164 sources[i] = new_ip(source, (source:find(":") and "IPv6") or "IPv4");
165 end
166 end
167 end
168
169 handle4 = adns.lookup(function (reply, err)
170 handle4 = nil;
171
172 -- COMPAT: This is a compromise for all you CNAME-(ab)users :)
173 if not (reply and reply[#reply] and reply[#reply].a) then
174 local count = max_dns_depth;
175 reply = dns.peek(connect_host, "CNAME", "IN");
176 while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do
177 log("debug", "Looking up %s (DNS depth is %d)", tostring(reply[#reply].cname), count);
178 reply = dns.peek(reply[#reply].cname, "A", "IN") or dns.peek(reply[#reply].cname, "CNAME", "IN");
179 count = count - 1;
180 end
181 end
182 -- end of CNAME resolving
183
184 if reply and reply[#reply] and reply[#reply].a then
185 for _, ip in ipairs(reply) do
186 log("debug", "DNS reply for %s gives us %s", connect_host, ip.a);
187 IPs[#IPs+1] = new_ip(ip.a, "IPv4");
188 end
189 end
190
191 if has_other then
192 if #IPs > 0 then
193 rfc3484_dest(host_session.ip_hosts, sources);
194 for i = 1, #IPs do
195 IPs[i] = {ip = IPs[i], port = connect_port};
196 end
197 host_session.ip_choice = 0;
198 s2sout.try_next_ip(host_session);
199 else
200 log("debug", "DNS lookup failed to get a response for %s", connect_host);
201 host_session.ip_hosts = nil;
202 if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can
203 log("debug", "No other records to try for %s - destroying", host_session.to_host);
204 err = err and (": "..err) or "";
205 s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
206 end
207 end
208 else
209 has_other = true;
210 end
211 end, connect_host, "A", "IN");
212
213 handle6 = adns.lookup(function (reply, err)
214 handle6 = nil;
215
216 if reply and reply[#reply] and reply[#reply].aaaa then
217 for _, ip in ipairs(reply) do
218 log("debug", "DNS reply for %s gives us %s", connect_host, ip.aaaa);
219 IPs[#IPs+1] = new_ip(ip.aaaa, "IPv6");
220 end
221 end
222
223 if has_other then
224 if #IPs > 0 then
225 rfc3484_dest(host_session.ip_hosts, sources);
226 for i = 1, #IPs do
227 IPs[i] = {ip = IPs[i], port = connect_port};
228 end
229 host_session.ip_choice = 0;
230 s2sout.try_next_ip(host_session);
231 else
232 log("debug", "DNS lookup failed to get a response for %s", connect_host);
233 host_session.ip_hosts = nil;
234 if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can
235 log("debug", "No other records to try for %s - destroying", host_session.to_host);
236 err = err and (": "..err) or "";
237 s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
238 end
239 end
240 else
241 has_other = true;
242 end
243 end, connect_host, "AAAA", "IN");
244
245 return true;
246 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
247 s2sout.try_next_ip(host_session);
248 else
249 host_session.ip_hosts = nil;
250 if not s2sout.attempt_connection(host_session, "out of IP addresses") then -- Retry if we can
251 log("debug", "No other records to try for %s - destroying", host_session.to_host);
252 err = err and (": "..err) or "";
253 s2s_destroy_session(host_session, "Connecting failed"..err); -- End of the line, we can't
254 return false;
255 end
256 end
257
258 return true;
259 end
260
261 function s2sout.make_connect(host_session, connect_host, connect_port)
262 (host_session.log or log)("info", "Beginning new connection attempt to %s ([%s]:%d)", host_session.to_host, connect_host.addr, connect_port);
263 -- Ok, we're going to try to connect
264
265 local from_host, to_host = host_session.from_host, host_session.to_host;
266
267 local conn, handler;
268 if connect_host.proto == "IPv4" then
269 conn, handler = socket.tcp();
270 else
271 conn, handler = socket.tcp6();
272 end
273
274 if not conn then
275 log("warn", "Failed to create outgoing connection, system error: %s", handler);
276 return false, handler;
277 end
278
279 conn:settimeout(0);
280 local success, err = conn:connect(connect_host.addr, connect_port);
281 if not success and err ~= "timeout" then
282 log("warn", "s2s connect() to %s (%s:%d) failed: %s", host_session.to_host, connect_host.addr, connect_port, err);
283 return false, err;
284 end
285
286 conn = wrapclient(conn, connect_host.addr, connect_port, s2s_listener, "*a");
287 host_session.conn = conn;
288
289 local filter = initialize_filters(host_session);
290 local w, log = conn.write, host_session.log;
291 host_session.sends2s = function (t)
292 log("debug", "sending: %s", (t.top_tag and t:top_tag()) or t:match("^[^>]*>?"));
293 if t.name then
294 t = filter("stanzas/out", t);
295 end
296 if t then
297 t = filter("bytes/out", tostring(t));
298 if t then
299 return w(conn, tostring(t));
300 end
301 end
302 end
303
304 -- Register this outgoing connection so that xmppserver_listener knows about it
305 -- otherwise it will assume it is a new incoming connection
306 s2s_listener.register_outgoing(conn, host_session);
307
308 host_session:open_stream(from_host, to_host);
309
310 log("debug", "Connection attempt in progress...");
311 return true;
312 end
313
314 return s2sout;