view mod_bidi/mod_bidi.lua @ 5401:c8d04ac200fc

mod_http_oauth2: Reject loopback URIs as client_uri This really should be a proper website with info, https://localhost is not good enough. Ideally we'd validate that it's got proper DNS and is actually reachable, but triggering HTTP or even DNS lookups seems like it would carry abuse potential that would best to avoid.
author Kim Alvefur <zash@zash.se>
date Tue, 02 May 2023 16:20:55 +0200
parents c96a53bf67b3
children
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-- 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;
		origin.outgoing = true;
	elseif origin.type == "s2sout" then -- handle incoming stanzas correctly
		local bidi_session = {
			type = "s2sin"; direction = "incoming";
			incoming = true;
			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
		if origin.incoming == true then
			module:log("warn", "This module can now be replaced by mod_s2s_bidi which is included with Prosody");
		end
		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
		if origin.outgoing == true then
			module:log("warn", "This module can now be replaced by mod_s2s_bidi which is included with Prosody");
		end
		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);