--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_bidi/mod_bidi.lua	Fri Jan 11 01:08:31 2013 +0100
@@ -0,0 +1,128 @@
+-- Bidirectional Server-to-Server Connections
+-- http://xmpp.org/extensions/xep-0288.html
+-- Copyright (C) 2013 Kim Alvefur
+--
+-- This file is MIT/X11 licensed.
+--
+local s2smanager = require"core.s2smanager";
+local add_filter = require "util.filters".add_filter;
+local st = require "util.stanza";
+local jid_split = require"util.jid".prepped_split;
+
+local xmlns_bidi_feature = "urn:xmpp:features:bidi"
+local xmlns_bidi = "urn:xmpp:bidi";
+local noop = function () end
+local core_process_stanza = prosody.core_process_stanza;
+
+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)
+	local bidi_session, remote_host;
+	origin.log("debug", "Creating bidirectional session wrapper");
+	if origin.direction == "incoming" then
+		remote_host = origin.from_host;
+		bidi_session = s2smanager.new_outgoing(origin.to_host, origin.from_host)
+	else -- outgoing
+		remote_host = origin.to_host;
+		bidi_session = s2smanager.new_incoming(origin.conn)
+		bidi_session.to_host = origin.from_host;
+		bidi_session.from_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
+	origin.bidi_session = bidi_session;
+	bidi_session.sends2s = origin.sends2s;
+	bidi_session.bounce_sendq = noop;
+	bidi_session.notopen = nil;
+	bidi_session.is_bidi = true;
+	bidi_session.bidi_session = false;
+	bidi_session.orig_session = origin;
+	bidi_session.secure = origin.secure;
+	bidi_session.cert_identity_status = origin.cert_identity_status;
+	bidi_session.cert_chain_status = origin.cert_chain_status;
+	bidi_session.close = function(...)
+		return origin.close(...);
+	end
+
+	bidi_session.log("info", "Bidirectional session established");
+	s2smanager.make_authenticated(bidi_session, remote_host);
+	return bidi_session;
+end
+
+-- Incoming s2s
+module:hook("s2s-stream-features", function(event)
+	local origin, features = event.origin, event.features;
+	if not origin.is_bidi and not hosts[module.host].s2sout[origin.from_host] 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 then
+		module:log("debug", "%s requested bidirectional stream", origin.from_host);
+		if hosts[module.host].s2sout[origin.from_host] then
+			local conflicting_session = hosts[module.host].s2sout[origin.from_host]
+			conflicting_session.log("warn", "We already have an outgoing connection to %s, closing it...", origin.from_host);
+			conflicting_session:close{ condition = "conflict", text = "Replaced by bidirectional stream" }
+			s2smanager.destroy_session(conflicting_session);
+		end
+		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 event.stanza:get_child("bidi", xmlns_bidi_feature) 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.bidi_session then
+		local bidi_session = session.bidi_session;
+		session.bidi_session = nil;
+		session.log("debug", "Tearing down bidirectional stream");
+		s2smanager.destroy_session(bidi_session, event.reason);
+	elseif session.orig_session then
+		local orig_session = session.orig_session;
+		session.orig_session = nil;
+		orig_session.log("debug", "Tearing down bidirectional stream");
+		s2smanager.destroy_session(orig_session, event.reason);
+	end
+end
+
+module:hook("s2sin-destroyed", disable_bidi);
+module:hook("s2sout-destroyed", disable_bidi);
+