-- 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:set_global();
local tostring, type = tostring, type;
local xpcall, traceback = xpcall, debug.traceback;
local add_task = require "util.timer".add_task;
local st = require "util.stanza";
local initialize_filters = require "util.filters".initialize;
local nameprep = require "util.encodings".stringprep.nameprep;
local new_xmpp_stream = require "util.xmppstream".new;
local s2s_new_incoming = require "core.s2smanager".new_incoming;
local s2s_new_outgoing = require "core.s2smanager".new_outgoing;
local s2s_destroy_session = require "core.s2smanager".destroy_session;
local uuid_gen = require "util.uuid".generate;
local cert_verify_identity = require "util.x509".verify_identity;
local s2sout = module:require("s2sout");
local connect_timeout = module:get_option_number("s2s_timeout", 60);
local sessions = module:shared("sessions");
--- Handle stanzas to remote domains
local bouncy_stanzas = { message = true, presence = true, iq = true };
local function bounce_sendq(session, reason)
local sendq = session.sendq;
if not sendq then return; end
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];
if reply and not(reply.attr.xmlns) and bouncy_stanzas[reply.name] then
reply.attr.type = "error";
reply:tag("error", {type = "cancel"})
:tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
if reason then
reply:tag("text", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"})
:text("Server-to-server connection failed: "..reason):up();
end
core_process_stanza(dummy, reply);
end
sendq[i] = nil;
end
session.sendq = nil;
end
function send_to_host(from_host, to_host, stanza)
if not hosts[from_host] then
log("warn", "Attempt to send stanza from %s - a host we don't serve", from_host);
return false;
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 (stanza.name ~= "db:verify" or not host.dialback_key) then
(host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host);
-- Queue stanza until we are able to send it
if host.sendq then t_insert(host.sendq, {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)});
else host.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} }; end
host.log("debug", "stanza [%s] queued ", stanza.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("error", "Stanza: %s", tostring(stanza));
return false;
else
(host.log or log)("debug", "going to send stanza to "..to_host.." from "..from_host);
-- FIXME
if host.from_host ~= from_host then
log("error", "WARNING! This might, possibly, be a bug, but it might not...");
log("error", "We are going to send from %s instead of %s", tostring(host.from_host), tostring(from_host));
end
host.sends2s(stanza);
host.log("debug", "stanza sent over "..host.type);
end
else
log("debug", "opening a new outgoing connection for this stanza");
local host_session = s2s_new_outgoing(from_host, to_host);
-- Store in buffer
host_session.bounce_sendq = bounce_sendq;
host_session.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} };
log("debug", "stanza [%s] queued until connection complete", tostring(stanza.name));
s2sout.initiate_connection(host_session);
if (not host_session.connecting) and (not host_session.conn) then
log("warn", "Connection to %s failed already, destroying session...", to_host);
if not s2s_destroy_session(host_session, "Connection failed") then
-- Already destroyed, we need to bounce our stanza
host_session:bounce_sendq(host_session.destruction_reason);
end
return false;
end
end
return true;
end
module:hook("route/remote", function (event)
return send_to_host(event.from_host, event.to_host, event.stanza);
end);
--- Helper to check that a session peer's certificate is valid
local function check_cert_status(session)
local conn = session.conn:socket()
local cert
if conn.getpeercertificate then
cert = conn:getpeercertificate()
end
if cert then
local chain_valid, errors = conn:getpeerverification()
-- Is there any interest in printing out all/the number of errors here?
if not chain_valid then
(session.log or log)("debug", "certificate chain validation result: invalid");
session.cert_chain_status = "invalid";
else
(session.log or log)("debug", "certificate chain validation result: valid");
session.cert_chain_status = "valid";
local host = session.direction == "incoming" and session.from_host or session.to_host
-- We'll go ahead and verify the asserted identity if the
-- connecting server specified one.
if host then
if cert_verify_identity(host, "xmpp-server", cert) then
session.cert_identity_status = "valid"
else
session.cert_identity_status = "invalid"
end
end
end
end
end
--- XMPP stream event handlers
local stream_callbacks = { default_ns = "jabber:server", handlestanza = core_process_stanza };
local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
function stream_callbacks.streamopened(session, attr)
local send = session.sends2s;
-- TODO: #29: SASL/TLS on s2s streams
session.version = tonumber(attr.version) or 0;
-- TODO: Rename session.secure to session.encrypted
if session.secure == false then
session.secure = true;
end
if session.direction == "incoming" then
-- Send a reply stream header
session.to_host = attr.to and nameprep(attr.to);
session.from_host = attr.from and nameprep(attr.from);
session.streamid = uuid_gen();
(session.log or log)("debug", "Incoming s2s received ");
if session.to_host then
if not hosts[session.to_host] then
-- Attempting to connect to a host we don't serve
session:close({
condition = "host-unknown";
text = "This host does not serve "..session.to_host
});
return;
elseif hosts[session.to_host].disallow_s2s then
-- Attempting to connect to a host that disallows s2s
session:close({
condition = "policy-violation";
text = "Server-to-server communication is not allowed to this host";
});
return;
end
end
if session.secure and not session.cert_chain_status then check_cert_status(session); end
send("");
send(stanza.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, to=session.from_host, version=(session.version > 0 and "1.0" or nil) }):top_tag());
if session.version >= 1.0 then
local features = st.stanza("stream:features");
if session.to_host then
hosts[session.to_host].events.fire_event("s2s-stream-features", { origin = session, features = features });
else
(session.log or log)("warn", "No 'to' on stream header from %s means we can't offer any features", session.from_host or "unknown host");
end
log("debug", "Sending stream features: %s", tostring(features));
send(features);
end
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;
if session.secure and not session.cert_chain_status then check_cert_status(session); end
-- 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 server is pre-1.0, don't wait for features, just do dialback
if session.version < 1.0 then
if not session.dialback_verifying then
log("debug", "Initiating dialback...");
initiate_dialback(session);
else
s2s_mark_connected(session);
end
end
end
session.notopen = nil;
session.send = function(stanza) send_to_host(session.to_host, session.from_host, stanza); end;
end
function stream_callbacks.streamclosed(session)
(session.log or log)("debug", "Received ");
session:close();
end
function stream_callbacks.streamdisconnected(session, err)
if err and err ~= "stream closed" then
(session.log or log)("debug", "s2s connection attempt failed: %s", err);
if s2sout.attempt_connection(session, err) then
(session.log or log)("debug", "...so we're going to try another target");
return true; -- Session lives for now
end
end
(session.log or log)("info", "s2s disconnected: %s->%s (%s)", tostring(session.from_host), tostring(session.to_host), tostring(err or "closed"));
if session.con then sessions[session.conn] = nil; else (session.log or log)("debug", "stale session's connection already closed"); end
s2s_destroy_session(session, err);
end
function stream_callbacks.error(session, error, data)
if error == "no-stream" then
session:close("invalid-namespace");
elseif error == "parse-error" then
session.log("debug", "Server-to-server XML parse error: %s", tostring(error));
session:close("not-well-formed");
elseif error == "stream-error" then
local condition, text = "undefined-condition";
for child in data:children() do
if child.attr.xmlns == xmlns_xmpp_streams then
if child.name ~= "text" then
condition = child.name;
else
text = child:get_text();
end
if condition ~= "undefined-condition" and text then
break;
end
end
end
text = condition .. (text and (" ("..text..")") or "");
session.log("info", "Session closed by remote with error: %s", text);
session:close(nil, text);
end
end
local function handleerr(err) log("error", "Traceback[s2s]: %s: %s", tostring(err), traceback()); end
function stream_callbacks.handlestanza(session, stanza)
if stanza.attr.xmlns == "jabber:client" then --COMPAT: Prosody pre-0.6.2 may send jabber:client
stanza.attr.xmlns = nil;
end
stanza = session.filter("stanzas/in", stanza);
if stanza then
return xpcall(function () return core_process_stanza(session, stanza) end, handleerr);
end
end
local listener = { default_port = 5269, default_mode = "*a", default_interface = "*" };
--- Session methods
local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
local default_stream_attr = { ["xmlns:stream"] = "http://etherx.jabber.org/streams", xmlns = stream_callbacks.default_ns, version = "1.0", id = "" };
local function session_close(session, reason, remote_reason)
local log = session.log or log;
if session.conn then
if session.notopen then
session.sends2s("");
session.sends2s(st.stanza("stream:stream", default_stream_attr):top_tag());
end
if reason then
if type(reason) == "string" then -- assume stream error
log("info", "Disconnecting %s[%s], is: %s", session.host or "(unknown host)", session.type, reason);
session.sends2s(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));
elseif type(reason) == "table" then
if reason.condition then
local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();
if reason.text then
stanza:tag("text", stream_xmlns_attr):text(reason.text):up();
end
if reason.extra then
stanza:add_child(reason.extra);
end
log("info", "Disconnecting %s[%s], is: %s", session.host or "(unknown host)", session.type, tostring(stanza));
session.sends2s(stanza);
elseif reason.name then -- a stanza
log("info", "Disconnecting %s->%s[%s], is: %s", session.from_host or "(unknown host)", session.to_host or "(unknown host)", session.type, tostring(reason));
session.sends2s(reason);
end
end
end
session.sends2s("");
if session.notopen or not session.conn:close() then
session.conn:close(true); -- Force FIXME: timer?
end
session.conn:close();
listener.ondisconnect(session.conn, remote_reason or (reason and (reason.text or reason.condition)) or reason or "stream closed");
end
end
-- Session initialization logic shared by incoming and outgoing
local function initialize_session(session)
local stream = new_xmpp_stream(session, stream_callbacks);
session.stream = stream;
session.notopen = true;
function session.reset_stream()
session.notopen = true;
session.stream:reset();
end
local filter = session.filter;
function session.data(data)
data = filter("bytes/in", data);
if data then
local ok, err = stream:feed(data);
if ok then return; end
(session.log or log)("warn", "Received invalid XML: %s", data);
(session.log or log)("warn", "Problem was: %s", err);
session:close("not-well-formed");
end
end
session.close = session_close;
local handlestanza = stream_callbacks.handlestanza;
function session.dispatch_stanza(session, stanza)
return handlestanza(session, stanza);
end
local conn = session.conn;
add_task(connect_timeout, function ()
if session.conn ~= conn or session.connecting
or session.type == "s2sin" or session.type == "s2sout" then
return; -- Ok, we're connect[ed|ing]
end
-- Not connected, need to close session and clean up
(session.log or log)("debug", "Destroying incomplete session %s->%s due to inactivity",
session.from_host or "(unknown)", session.to_host or "(unknown)");
session:close("connection-timeout");
end);
end
function listener.onconnect(conn)
if not sessions[conn] then -- May be an existing outgoing session
local session = s2s_new_incoming(conn);
sessions[conn] = session;
session.log("debug", "Incoming s2s connection");
local filter = initialize_filters(session);
local w = conn.write;
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, t);
end
end
end
initialize_session(session);
end
end
function listener.onincoming(conn, data)
local session = sessions[conn];
if session then
session.data(data);
end
end
function listener.onstatus(conn, status)
if status == "ssl-handshake-complete" then
local session = sessions[conn];
if session and session.direction == "outgoing" then
local to_host, from_host = session.to_host, session.from_host;
session.log("debug", "Sending stream header...");
session:open_stream(session.from_host, session.to_host);
end
end
end
function listener.ondisconnect(conn, err)
local session = sessions[conn];
if session then
if stream_callbacks.streamdisconnected(session, err) then
return; -- Connection lives, for now
end
end
sessions[conn] = nil;
end
function listener.register_outgoing(conn, session)
session.direction = "outgoing";
sessions[conn] = session;
initialize_session(session);
end
s2sout.set_listener(listener);
require "core.portmanager".register_service("s2s", {
listener = listener;
default_port = 5269;
encryption = "starttls";
});