+-- Prosody IM
+-- Copyright (C) 2008-2009 Matthew Wild
+-- Copyright (C) 2008-2009 Waqas Hussain
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+
local hosts = hosts;
local sessions = sessions;
+local core_process_stanza = function(a, b) core_process_stanza(a, b); end
+local add_task = require "util.timer".add_task;
local socket = require "socket";
local format = string.format;
local t_insert, t_sort = table.insert, table.sort;
local get_traceback = debug.traceback;
-local tostring, pairs, ipairs, getmetatable, print, newproxy, error, tonumber
- = tostring, pairs, ipairs, getmetatable, print, newproxy, error, tonumber;
+local tostring, pairs, ipairs, getmetatable, newproxy, error, tonumber
+ = tostring, pairs, ipairs, getmetatable, newproxy, error, tonumber;
+local idna_to_ascii = require "util.encodings".idna.to_ascii;
local connlisteners_get = require "net.connlisteners".get;
-local wraptlsclient = require "net.server".wraptlsclient;
+local wrapclient = require "net.server".wrapclient;
local modulemanager = require "core.modulemanager";
local st = require "stanza";
local stanza = st.stanza;
+local nameprep = require "util.encodings".stringprep.nameprep;
local uuid_gen = require "util.uuid".generate;
local log = logger_init("s2smanager");
-local md5_hash = require "util.hashes".md5;
+local sha256_hash = require "util.hashes".sha256;
+
+local dialback_secret = uuid_gen();
-local dialback_secret = "This is very secret!!! Ha!";
+local adns, dns = require "net.adns", require "net.dns";
-local dns = require "net.dns";
+local connect_timeout = config.get("*", "core", "s2s_timeout") or 60;
+local dns_timeout = config.get("*", "core", "dns_timeout") or 60;
+local max_dns_depth = config.get("*", "core", "dns_max_depth") or 3;
+
+incoming_s2s = {};
+local incoming_s2s = incoming_s2s;
module "s2smanager"
local function compare_srv_priorities(a,b) return a.priority < b.priority or a.weight < b.weight; end
+local function bounce_sendq(session)
+ local sendq = session.sendq;
+ if sendq then
+ session.log("info", "sending error replies for "..#sendq.." queued stanzas because of failed outgoing connection to "..tostring(session.to_host));
+ local dummy = {
+ type = "s2sin";
+ send = function(s)
+ (session.log or log)("error", "Replying to to an s2s error reply, please report this! Traceback: %s", get_traceback());
+ end;
+ dummy = true;
+ };
+ for i, data in ipairs(sendq) do
+ local reply = data[2];
+ local xmlns = reply.attr.xmlns;
+ if not xmlns or xmlns == "jabber:client" or xmlns == "jabber:server" then
+ reply.attr.type = "error";
+ reply:tag("error", {type = "cancel"})
+ :tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
+ core_process_stanza(dummy, reply);
+ end
+ sendq[i] = nil;
+ end
+ session.sendq = nil;
+ end
+end
+
function send_to_host(from_host, to_host, data)
- if data.name then data = tostring(data); end
local host = hosts[from_host].s2sout[to_host];
if host then
-- We have a connection to this host already
- if host.type == "s2sout_unauthed" and ((not data.xmlns) or data.xmlns == "jabber:client" or data.xmlns == "jabber:server") then
- (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host..", authing it now...");
- if not host.notopen and not host.dialback_key then
+ if host.type == "s2sout_unauthed" and data.name ~= "db:verify" and ((not data.xmlns) or data.xmlns == "jabber:client" or data.xmlns == "jabber:server") then
+ (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host);
+ if not host.notopen and not host.dialback_key and host.sends2s then
host.log("debug", "dialback had not been initiated");
initiate_dialback(host);
end
-- Queue stanza until we are able to send it
- if host.sendq then t_insert(host.sendq, data);
- else host.sendq = { data }; end
+ if host.sendq then t_insert(host.sendq, {tostring(data), st.reply(data)});
+ else host.sendq = { {tostring(data), st.reply(data)} }; end
+ host.log("debug", "stanza [%s] queued ", data.name);
elseif host.type == "local" or host.type == "component" then
log("error", "Trying to send a stanza to ourselves??")
log("error", "Traceback: %s", get_traceback());
log("debug", "opening a new outgoing connection for this stanza");
local host_session = new_outgoing(from_host, to_host);
-- Store in buffer
- host_session.sendq = { data };
+ host_session.sendq = { {tostring(data), st.reply(data)} };
+ log("debug", "stanza [%s] queued until connection complete", tostring(data.name));
+ if (not host_session.connecting) and (not host_session.conn) then
+ log("warn", "Connection to %s failed already, destroying session...", to_host);
+ destroy_session(host_session);
+ end
end
end
local open_sessions = 0;
function new_incoming(conn)
- local session = { conn = conn, type = "s2sin_unauthed", direction = "incoming" };
+ local session = { conn = conn, type = "s2sin_unauthed", direction = "incoming", hosts = {} };
if true then
session.trace = newproxy(true);
- getmetatable(session.trace).__gc = function () open_sessions = open_sessions - 1; print("s2s session got collected, now "..open_sessions.." s2s sessions are allocated") end;
+ getmetatable(session.trace).__gc = function () open_sessions = open_sessions - 1; end;
end
open_sessions = open_sessions + 1;
local w, log = conn.write, logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$"));
+ session.log = log;
session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
+ incoming_s2s[session] = true;
+ add_task(connect_timeout, function ()
+ if session.conn ~= conn or
+ session.type == "s2sin" then
+ return; -- Ok, we're connect[ed|ing]
+ end
+ -- Not connected, need to close session and clean up
+ (session.log or log)("warn", "Destroying incomplete session %s->%s due to inactivity",
+ session.from_host or "(unknown)", session.to_host or "(unknown)");
+ session:close("connection-timeout");
+ end);
return session;
end
function new_outgoing(from_host, to_host)
local host_session = { to_host = to_host, from_host = from_host, notopen = true, type = "s2sout_unauthed", direction = "outgoing" };
hosts[from_host].s2sout[to_host] = host_session;
- local cl = connlisteners_get("xmppserver");
-
- local conn, handler = socket.tcp()
-
- --FIXME: Below parameters (ports/ip) are incorrect (use SRV)
- local connect_host, connect_port = to_host, 5269;
+ local log;
+ do
+ local conn_name = "s2sout"..tostring(host_session):match("[a-f0-9]*$");
+ log = logger_init(conn_name);
+ host_session.log = log;
+ end
- local answer = dns.lookup("_xmpp-server._tcp."..to_host..".", "SRV");
+ -- This is the first call, can't fail (the first step is DNS lookup)
+ attempt_connection(host_session);
- 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);
+ 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
- t_sort(srv_hosts, compare_srv_priorities);
- local srv_choice = srv_hosts[1];
- if srv_choice then
- log("debug", "Best record found");
- 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
- end
-
- conn:settimeout(0);
- local success, err = conn:connect(connect_host, connect_port);
- if not success and err ~= "timeout" then
- log("warn", "s2s connect() failed: %s", err);
end
+
+ return host_session;
+end
+
+
+function attempt_connection(host_session, err)
+ local from_host, to_host = host_session.from_host, host_session.to_host;
+ local connect_host, connect_port = idna_to_ascii(to_host), 5269;
+
+ 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
+ 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 = try_connect(host_session, connect_host, connect_port);
+ if not ok then
+ if not attempt_connection(host_session, err) then
+ -- No more attempts will be made
+ destroy_session(host_session);
+ end
+ end
+ end, "_xmpp-server._tcp."..connect_host..".", "SRV");
- conn = wraptlsclient(cl, conn, to_host, 5269, 0, 1, hosts[from_host].ssl_ctx );
- host_session.conn = conn;
+ -- Set handler for DNS timeout
+ add_task(dns_timeout, function ()
+ if handle then
+ adns.cancel(handle, true);
+ end
+ end);
- -- Register this outgoing connection so that xmppserver_listener knows about it
- -- otherwise it will assume it is a new incoming connection
- cl.register_outgoing(conn, host_session);
+ log("debug", "DNS lookup for %s sent, waiting for response before we can connect", to_host);
+ return true; -- Attempt in progress
+ 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 try_connect(host_session, connect_host, connect_port);
+end
+
+function try_connect(host_session, connect_host, connect_port)
+ host_session.connecting = true;
+ local handle;
+ handle = adns.lookup(function (reply)
+ handle = nil;
+ host_session.connecting = nil;
- local log;
- do
- local conn_name = "s2sout"..tostring(conn):match("[a-f0-9]*$");
- log = logger_init(conn_name);
- host_session.log = log;
+ -- 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
- local w = conn.write;
- host_session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
+ if reply and reply[#reply] and reply[#reply].a then
+ log("debug", "DNS reply for %s gives us %s", connect_host, reply[#reply].a);
+ return make_connect(host_session, reply[#reply].a, connect_port);
+ else
+ log("debug", "DNS lookup failed to get a response for %s", connect_host);
+ if not 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);
+ destroy_session(host_session); -- End of the line, we can't
+ end
+ end
+ end, connect_host, "A", "IN");
+
+ -- Set handler for DNS timeout
+ add_task(dns_timeout, function ()
+ if handle then
+ adns.cancel(handle, true);
+ end
+ end);
- conn.write(format([[<stream:stream xmlns='jabber:server' xmlns:db='jabber:server:dialback' xmlns:stream='http://etherx.jabber.org/streams' from='%s' to='%s' version='1.0'>]], from_host, to_host));
-
- return host_session;
+ return true;
+end
+
+function make_connect(host_session, connect_host, connect_port)
+ host_session.log("info", "Beginning new connection attempt to %s (%s:%d)", host_session.to_host, connect_host, 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 = socket.tcp()
+
+ conn:settimeout(0);
+ local success, err = conn:connect(connect_host, 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, connect_port, err);
+ return false, err;
+ end
+
+ local cl = connlisteners_get("xmppserver");
+ conn = wrapclient(conn, connect_host, connect_port, cl, cl.default_mode or 1, hosts[from_host].ssl_ctx, false );
+ host_session.conn = conn;
+
+ -- Register this outgoing connection so that xmppserver_listener knows about it
+ -- otherwise it will assume it is a new incoming connection
+ cl.register_outgoing(conn, host_session);
+
+ local w = conn.write;
+ host_session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
+
+ conn.write(format([[<stream:stream xmlns='jabber:server' xmlns:db='jabber:server:dialback' xmlns:stream='http://etherx.jabber.org/streams' from='%s' to='%s' version='1.0' xml:lang='en'>]], from_host, to_host));
+ log("debug", "Connection attempt in progress...");
+ add_task(connect_timeout, function ()
+ if host_session.conn ~= conn or
+ host_session.type == "s2sout" or
+ host_session.connecting then
+ return; -- Ok, we're connect[ed|ing]
+ end
+ -- Not connected, need to close session and clean up
+ (host_session.log or log)("warn", "Destroying incomplete session %s->%s due to inactivity",
+ host_session.from_host or "(unknown)", host_session.to_host or "(unknown)");
+ host_session:close("connection-timeout");
+ end);
+ return true;
end
function streamopened(session, attr)
local send = session.sends2s;
- session.version = tonumber(attr.version) or 0;
+ -- TODO: #29: SASL/TLS on s2s streams
+ session.version = 0; --tonumber(attr.version) or 0;
+
if session.version >= 1.0 and not (attr.to and attr.from) then
- print("to: "..tostring(attr.to).." from: "..tostring(attr.from));
- --error(session.to_host.." failed to specify 'to' or 'from' hostname as per RFC");
log("warn", (session.to_host or "(unknown)").." failed to specify 'to' or 'from' hostname as per RFC");
end
if session.direction == "incoming" then
-- Send a reply stream header
-
- for k,v in pairs(attr) do print("", tostring(k), ":::", tostring(v)); end
-
- session.to_host = attr.to;
- session.from_host = attr.from;
+ session.to_host = attr.to and nameprep(attr.to);
+ session.from_host = attr.from and nameprep(attr.from);
session.streamid = uuid_gen();
- print(session, session.from_host, "incoming s2s stream opened");
+ (session.log or log)("debug", "incoming s2s received <stream:stream>");
send("<?xml version='1.0'?>");
- send(stanza("stream:stream", { xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback', ["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.to_host }):top_tag());
+ send(stanza("stream:stream", { xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
+ ["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.to_host }):top_tag());
if session.to_host and not hosts[session.to_host] then
-- Attempting to connect to a host we don't serve
- session:close("host-unknown");
+ session:close({ condition = "host-unknown"; text = "This host does not serve "..session.to_host });
return;
end
if session.version >= 1.0 then
send(st.stanza("stream:features")
:tag("dialback", { xmlns='urn:xmpp:features:dialback' }):tag("optional"):up():up());
end
- --[[
- local features = {};
- modulemanager.fire_event("stream-features-s2s", session, features);
-
- send("<stream:features>");
-
- for _, feature in ipairs(features) do
- send(tostring(feature));
- end
-
- send("</stream:features>");
- ]]
elseif session.direction == "outgoing" then
-- If we are just using the connection for verifying dialback keys, we won't try and auth it
if not attr.id then error("stream response did not give us a streamid!!!"); end
session.streamid = attr.id;
+ -- Send unauthed buffer
+ -- (stanzas which are fine to send before dialback)
+ -- Note that this is *not* the stanza queue (which
+ -- we can only send if auth succeeds) :)
+ local send_buffer = session.send_buffer;
+ if send_buffer and #send_buffer > 0 then
+ log("debug", "Sending s2s send_buffer now...");
+ for i, data in ipairs(send_buffer) do
+ session.sends2s(tostring(data));
+ send_buffer[i] = nil;
+ end
+ end
+ session.send_buffer = nil;
+
if not session.dialback_verifying then
initiate_dialback(session);
else
session.notopen = nil;
end
+function streamclosed(session)
+ (session.log or log)("debug", "</stream:stream>");
+ if session.sends2s then
+ session.sends2s("</stream:stream>");
+ end
+ session.notopen = true;
+end
+
function initiate_dialback(session)
-- generate dialback key
session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
end
function generate_dialback(id, to, from)
- return md5_hash(id..to..from..dialback_secret); -- FIXME: See XEP-185 and XEP-220
+ return sha256_hash(id..to..from..dialback_secret, true);
end
function verify_dialback(id, to, from, key)
return key == generate_dialback(id, to, from);
end
-function make_authenticated(session)
+function make_authenticated(session, host)
if session.type == "s2sout_unauthed" then
session.type = "s2sout";
elseif session.type == "s2sin_unauthed" then
session.type = "s2sin";
+ if host then
+ session.hosts[host].authed = true;
+ end
+ elseif session.type == "s2sin" and host then
+ session.hosts[host].authed = true;
else
return false;
end
- session.log("info", "connection is now authenticated");
+ session.log("debug", "connection %s->%s is now authenticated", session.from_host or "(unknown)", session.to_host or "(unknown)");
mark_connected(session);
local from, to = session.from_host, session.to_host;
- session.log("debug", session.direction.." s2s connection "..from.."->"..to.." is now complete");
+ session.log("info", session.direction.." s2s connection "..from.."->"..to.." complete");
local send_to_host = send_to_host;
function session.send(data) send_to_host(to, from, data); end
if sendq then
session.log("debug", "sending "..#sendq.." queued stanzas across new outgoing connection to "..session.to_host);
for i, data in ipairs(sendq) do
- send(data);
+ send(data[1]);
sendq[i] = nil;
end
session.sendq = nil;
end
+
+ session.srv_hosts = nil;
end
end
function destroy_session(session)
(session.log or log)("info", "Destroying "..tostring(session.direction).." session "..tostring(session.from_host).."->"..tostring(session.to_host));
- -- FIXME: Flush sendq here/report errors to originators
-
if session.direction == "outgoing" then
hosts[session.from_host].s2sout[session.to_host] = nil;
+ bounce_sendq(session);
+ elseif session.direction == "incoming" then
+ incoming_s2s[session] = nil;
end
for k in pairs(session) do