-- Bidirectional Server-to-Server Connections
-- http://xmpp.org/extensions/xep-0288.html
-- Copyright (C) 2013 Kim Alvefur
--
-- This file is MIT/X11 licensed.
--
local add_filter = require "util.filters".add_filter;
local st = require "util.stanza";
local jid_split = require"util.jid".prepped_split;
local core_process_stanza = prosody.core_process_stanza;
local traceback = debug.traceback;
local hosts = hosts;
local xmlns_bidi_feature = "urn:xmpp:features:bidi"
local xmlns_bidi = "urn:xmpp:bidi";
local secure_only = module:get_option_boolean("secure_bidi_only", true);
local disable_bidi_for = module:get_option_set("no_bidi_with", { });
local bidi_sessions = module:shared"sessions-cache";
local function handleerr(err) log("error", "Traceback[s2s]: %s: %s", tostring(err), traceback()); end
local function 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 function new_bidi(origin)
if origin.type == "s2sin" then -- then we create an "outgoing" bidirectional session
local conflicting_session = hosts[origin.to_host].s2sout[origin.from_host]
if conflicting_session then
conflicting_session.log("info", "We already have an outgoing connection to %s, closing it...", origin.from_host);
conflicting_session:close{ condition = "conflict", text = "Replaced by bidirectional stream" }
end
bidi_sessions[origin.from_host] = origin;
origin.is_bidi = true;
elseif origin.type == "s2sout" then -- handle incoming stanzas correctly
local bidi_session = {
type = "s2sin"; direction = "incoming";
is_bidi = true; orig_session = origin;
to_host = origin.from_host;
from_host = origin.to_host;
hosts = {};
}
origin.bidi_session = bidi_session;
setmetatable(bidi_session, { __index = origin });
module:fire_event("s2s-authenticated", { session = bidi_session, host = origin.to_host });
local remote_host = origin.to_host;
add_filter(origin, "stanzas/in", function(stanza)
if stanza.attr.xmlns ~= nil then return stanza end
local _, host = jid_split(stanza.attr.from);
if host ~= remote_host then return stanza end
handlestanza(bidi_session, stanza);
end, 1);
end
end
module:hook("route/remote", function(event)
local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
if from_host ~= module.host then return end
local to_session = bidi_sessions[to_host];
if not to_session or to_session.type ~= "s2sin" then return end
if to_session.sends2s(stanza) then return true end
end, -2);
-- Incoming s2s
module:hook("s2s-stream-features", function(event)
local origin, features = event.origin, event.features;
if not origin.is_bidi and not origin.bidi_session and not origin.do_bidi
and not hosts[module.host].s2sout[origin.from_host]
and not disable_bidi_for:contains(origin.from_host)
and (not secure_only or (origin.cert_chain_status == "valid"
and origin.cert_identity_status == "valid")) then
module:log("debug", "Announcing support for bidirectional streams");
features:tag("bidi", { xmlns = xmlns_bidi_feature }):up();
end
end);
module:hook("stanza/urn:xmpp:bidi:bidi", function(event)
local origin = event.session or event.origin;
if not origin.is_bidi and not origin.bidi_session
and not disable_bidi_for:contains(origin.from_host)
and (not secure_only or origin.cert_chain_status == "valid"
and origin.cert_identity_status == "valid") then
module:log("debug", "%s requested bidirectional stream", origin.from_host);
origin.do_bidi = true;
return true;
end
end);
-- Outgoing s2s
module:hook("stanza/http://etherx.jabber.org/streams:features", function(event)
local origin = event.session or event.origin;
if not ( origin.bidi_session or origin.is_bidi or origin.do_bidi)
and not disable_bidi_for:contains(origin.to_host)
and event.stanza:get_child("bidi", xmlns_bidi_feature)
and (not secure_only or origin.cert_chain_status == "valid"
and origin.cert_identity_status == "valid") then
module:log("debug", "%s supports bidirectional streams", origin.to_host);
origin.sends2s(st.stanza("bidi", { xmlns = xmlns_bidi }));
origin.do_bidi = true;
end
end, 160);
function enable_bidi(event)
local session = event.session;
if session.do_bidi and not ( session.is_bidi or session.bidi_session ) then
session.do_bidi = nil;
new_bidi(session);
end
end
module:hook("s2sin-established", enable_bidi);
module:hook("s2sout-established", enable_bidi);
function disable_bidi(event)
local session = event.session;
if session.type == "s2sin" then
bidi_sessions[session.from_host] = nil;
end
end
module:hook("s2sin-destroyed", disable_bidi);
module:hook("s2sout-destroyed", disable_bidi);