--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/s2s/s2sout.lib.lua Mon Jan 23 16:28:20 2012 +0000
@@ -0,0 +1,314 @@
+-- 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 containing all the logic for connecting to a remote server
+
+local initialize_filters = require "util.filters".initialize;
+local idna_to_ascii = require "util.encodings".idna.to_ascii;
+local add_task = require "util.timer".add_task;
+local socket = require "socket";
+
+local s2s_destroy_session = require "core.s2smanager".destroy_session;
+
+local s2sout = {};
+
+local s2s_listener;
+
+function s2sout.set_listener(listener)
+ s2s_listener = listener;
+end
+
+local function compare_srv_priorities(a,b)
+ return a.priority < b.priority or (a.priority == b.priority and a.weight > b.weight);
+end
+
+local function session_open_stream(session, from, to)
+ session.sends2s(st.stanza("stream:stream", {
+ xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
+ ["xmlns:stream"]='http://etherx.jabber.org/streams',
+ from=from, to=to, version='1.0', ["xml:lang"]='en'}):top_tag());
+end
+
+function s2sout.initiate_connection(host_session)
+ initialize_filters(host_session);
+ session.open_stream = session_open_stream;
+
+ -- Kick the connection attempting machine into life
+ if not s2sout.attempt_connection(host_session) then
+ -- Intentionally not returning here, the
+ -- session is needed, connected or not
+ s2s_destroy_session(host_session);
+ end
+
+ if not host_session.sends2s then
+ -- A sends2s which buffers data (until the stream is opened)
+ -- note that data in this buffer will be sent before the stream is authed
+ -- and will not be ack'd in any way, successful or otherwise
+ local buffer;
+ function host_session.sends2s(data)
+ if not buffer then
+ buffer = {};
+ host_session.send_buffer = buffer;
+ end
+ log("debug", "Buffering data on unconnected s2sout to %s", to_host);
+ buffer[#buffer+1] = data;
+ log("debug", "Buffered item %d: %s", #buffer, tostring(data));
+ end
+ end
+end
+
+function s2sout.attempt_connection(host_session, err)
+ local from_host, to_host = host_session.from_host, host_session.to_host;
+ local connect_host, connect_port = to_host and idna_to_ascii(to_host), 5269;
+
+ if not connect_host then
+ return false;
+ end
+
+ if not err then -- This is our first attempt
+ log("debug", "First attempt to connect to %s, starting with SRV lookup...", to_host);
+ host_session.connecting = true;
+ local handle;
+ handle = adns.lookup(function (answer)
+ handle = nil;
+ host_session.connecting = nil;
+ if answer then
+ log("debug", to_host.." has SRV records, handling...");
+ local srv_hosts = {};
+ host_session.srv_hosts = srv_hosts;
+ for _, record in ipairs(answer) do
+ t_insert(srv_hosts, record.srv);
+ end
+ if #srv_hosts == 1 and srv_hosts[1].target == "." then
+ log("debug", to_host.." does not provide a XMPP service");
+ s2s_destroy_session(host_session, err); -- Nothing to see here
+ return;
+ end
+ t_sort(srv_hosts, compare_srv_priorities);
+
+ local srv_choice = srv_hosts[1];
+ host_session.srv_choice = 1;
+ if srv_choice then
+ connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
+ log("debug", "Best record found, will connect to %s:%d", connect_host, connect_port);
+ end
+ else
+ log("debug", to_host.." has no SRV records, falling back to A");
+ end
+ -- Try with SRV, or just the plain hostname if no SRV
+ local ok, err = s2sout.try_connect(host_session, connect_host, connect_port);
+ if not ok then
+ if not s2sout.attempt_connection(host_session, err) then
+ -- No more attempts will be made
+ s2s_destroy_session(host_session, err);
+ end
+ end
+ end, "_xmpp-server._tcp."..connect_host..".", "SRV");
+
+ return true; -- Attempt in progress
+ elseif host_session.ip_hosts then
+ return s2sout.try_connect(host_session, connect_host, connect_port, err);
+ elseif host_session.srv_hosts and #host_session.srv_hosts > host_session.srv_choice then -- Not our first attempt, and we also have SRV
+ host_session.srv_choice = host_session.srv_choice + 1;
+ local srv_choice = host_session.srv_hosts[host_session.srv_choice];
+ connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
+ host_session.log("info", "Connection failed (%s). Attempt #%d: This time to %s:%d", tostring(err), host_session.srv_choice, connect_host, connect_port);
+ else
+ host_session.log("info", "Out of connection options, can't connect to %s", tostring(host_session.to_host));
+ -- We're out of options
+ return false;
+ end
+
+ if not (connect_host and connect_port) then
+ -- Likely we couldn't resolve DNS
+ 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));
+ return false;
+ end
+
+ return s2sout.try_connect(host_session, connect_host, connect_port);
+end
+
+function s2sout.try_next_ip(host_session)
+ host_session.connecting = nil;
+ host_session.ip_choice = host_session.ip_choice + 1;
+ local ip = host_session.ip_hosts[host_session.ip_choice];
+ local ok, err= s2sout.make_connect(host_session, ip.ip, ip.port);
+ if not ok then
+ if not s2sout.attempt_connection(host_session, err or "closed") then
+ err = err and (": "..err) or "";
+ s2s_destroy_session(host_session, "Connection failed"..err);
+ end
+ end
+end
+
+function s2sout.try_connect(host_session, connect_host, connect_port, err)
+ host_session.connecting = true;
+
+ if not err then
+ local IPs = {};
+ host_session.ip_hosts = IPs;
+ local handle4, handle6;
+ local has_other = false;
+
+ if not sources then
+ sources = {};
+ for i, source in ipairs(cfg_sources) do
+ if source == "*" then
+ sources[i] = new_ip("0.0.0.0", "IPv4");
+ else
+ sources[i] = new_ip(source, (source:find(":") and "IPv6") or "IPv4");
+ end
+ end
+ end
+
+ handle4 = adns.lookup(function (reply, err)
+ handle4 = nil;
+
+ -- COMPAT: This is a compromise for all you CNAME-(ab)users :)
+ if not (reply and reply[#reply] and reply[#reply].a) then
+ local count = max_dns_depth;
+ reply = dns.peek(connect_host, "CNAME", "IN");
+ while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do
+ log("debug", "Looking up %s (DNS depth is %d)", tostring(reply[#reply].cname), count);
+ reply = dns.peek(reply[#reply].cname, "A", "IN") or dns.peek(reply[#reply].cname, "CNAME", "IN");
+ count = count - 1;
+ end
+ end
+ -- end of CNAME resolving
+
+ if reply and reply[#reply] and reply[#reply].a then
+ for _, ip in ipairs(reply) do
+ log("debug", "DNS reply for %s gives us %s", connect_host, ip.a);
+ IPs[#IPs+1] = new_ip(ip.a, "IPv4");
+ end
+ end
+
+ if has_other then
+ if #IPs > 0 then
+ rfc3484_dest(host_session.ip_hosts, sources);
+ for i = 1, #IPs do
+ IPs[i] = {ip = IPs[i], port = connect_port};
+ end
+ host_session.ip_choice = 0;
+ s2sout.try_next_ip(host_session);
+ else
+ log("debug", "DNS lookup failed to get a response for %s", connect_host);
+ host_session.ip_hosts = nil;
+ if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can
+ log("debug", "No other records to try for %s - destroying", host_session.to_host);
+ err = err and (": "..err) or "";
+ s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
+ end
+ end
+ else
+ has_other = true;
+ end
+ end, connect_host, "A", "IN");
+
+ handle6 = adns.lookup(function (reply, err)
+ handle6 = nil;
+
+ if reply and reply[#reply] and reply[#reply].aaaa then
+ for _, ip in ipairs(reply) do
+ log("debug", "DNS reply for %s gives us %s", connect_host, ip.aaaa);
+ IPs[#IPs+1] = new_ip(ip.aaaa, "IPv6");
+ end
+ end
+
+ if has_other then
+ if #IPs > 0 then
+ rfc3484_dest(host_session.ip_hosts, sources);
+ for i = 1, #IPs do
+ IPs[i] = {ip = IPs[i], port = connect_port};
+ end
+ host_session.ip_choice = 0;
+ s2sout.try_next_ip(host_session);
+ else
+ log("debug", "DNS lookup failed to get a response for %s", connect_host);
+ host_session.ip_hosts = nil;
+ if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can
+ log("debug", "No other records to try for %s - destroying", host_session.to_host);
+ err = err and (": "..err) or "";
+ s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
+ end
+ end
+ else
+ has_other = true;
+ end
+ end, connect_host, "AAAA", "IN");
+
+ return true;
+ 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
+ s2sout.try_next_ip(host_session);
+ else
+ host_session.ip_hosts = nil;
+ if not s2sout.attempt_connection(host_session, "out of IP addresses") then -- Retry if we can
+ log("debug", "No other records to try for %s - destroying", host_session.to_host);
+ err = err and (": "..err) or "";
+ s2s_destroy_session(host_session, "Connecting failed"..err); -- End of the line, we can't
+ return false;
+ end
+ end
+
+ return true;
+end
+
+function s2sout.make_connect(host_session, connect_host, connect_port)
+ (host_session.log or log)("info", "Beginning new connection attempt to %s ([%s]:%d)", host_session.to_host, connect_host.addr, connect_port);
+ -- Ok, we're going to try to connect
+
+ local from_host, to_host = host_session.from_host, host_session.to_host;
+
+ local conn, handler;
+ if connect_host.proto == "IPv4" then
+ conn, handler = socket.tcp();
+ else
+ conn, handler = socket.tcp6();
+ end
+
+ if not conn then
+ log("warn", "Failed to create outgoing connection, system error: %s", handler);
+ return false, handler;
+ end
+
+ conn:settimeout(0);
+ local success, err = conn:connect(connect_host.addr, connect_port);
+ if not success and err ~= "timeout" then
+ log("warn", "s2s connect() to %s (%s:%d) failed: %s", host_session.to_host, connect_host.addr, connect_port, err);
+ return false, err;
+ end
+
+ conn = wrapclient(conn, connect_host.addr, connect_port, s2s_listener, "*a");
+ host_session.conn = conn;
+
+ local filter = initialize_filters(host_session);
+ local w, log = conn.write, host_session.log;
+ host_session.sends2s = function (t)
+ log("debug", "sending: %s", (t.top_tag and t:top_tag()) or t:match("^[^>]*>?"));
+ if t.name then
+ t = filter("stanzas/out", t);
+ end
+ if t then
+ t = filter("bytes/out", tostring(t));
+ if t then
+ return w(conn, tostring(t));
+ end
+ end
+ end
+
+ -- Register this outgoing connection so that xmppserver_listener knows about it
+ -- otherwise it will assume it is a new incoming connection
+ s2s_listener.register_outgoing(conn, host_session);
+
+ host_session:open_stream(from_host, to_host);
+
+ log("debug", "Connection attempt in progress...");
+ return true;
+end
+
+return s2sout;