-- Prosody IM v0.4 -- 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 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 idna_to_ascii = require "util.encodings".idna.to_ascii; local connlisteners_get = require "net.connlisteners".get; local wrapclient = require "net.server".wrapclient; local modulemanager = require "core.modulemanager"; local st = require "stanza"; local stanza = st.stanza; local uuid_gen = require "util.uuid".generate; local logger_init = require "util.logger".init; local log = logger_init("s2smanager"); local sha256_hash = require "util.hashes".sha256; local dialback_secret = sha256_hash(tostring{} .. math.random() .. socket.gettime(), true); local dns = require "net.dns"; 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("debug", "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) 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 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 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, {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("error", "Stanza: %s", tostring(data)); 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(data); host.log("debug", "stanza sent over "..host.type); end else 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 = { {tostring(data), st.reply(data)} }; if not host_session.conn then destroy_session(host_session); end end end local open_sessions = 0; function new_incoming(conn) 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; end; end open_sessions = open_sessions + 1; local w, log = conn.write, logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$")); session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end incoming_s2s[session] = true; return session; end function new_outgoing(from_host, to_host) local host_session = { to_host = to_host, from_host = from_host, notopen = true, type = "s2sout_unauthed", direction = "outgoing" }; hosts[from_host].s2sout[to_host] = host_session; local log; do local conn_name = "s2sout"..tostring(host_session):match("[a-f0-9]*$"); log = logger_init(conn_name); host_session.log = log; end attempt_connection(host_session); return host_session; end function attempt_connection(host_session, err) local from_host, to_host = host_session.from_host, host_session.to_host; local conn, handler = socket.tcp() local connect_host, connect_port = idna_to_ascii(to_host), 5269; if not err then -- This is our first attempt local answer = dns.lookup("_xmpp-server._tcp."..connect_host..".", "SRV"); 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 end 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("debug", "Connection failed (%s). Attempt #%d: This time to %s:%d", tostring(err), host_session.srv_choice, connect_host, connect_port); else host_session.log("debug", "Out of connection options, can't connect to %s", tostring(host_session.to_host)); -- We're out of options return false; end -- Ok, we're going to try to connect 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); return false; 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'>]], from_host, to_host)); return true; end function streamopened(session, attr) local send = session.sends2s; -- 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 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 session.to_host = attr.to; session.from_host = attr.from; session.streamid = uuid_gen(); (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()); if session.to_host and 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; end if session.version >= 1.0 then send(st.stanza("stream:features") :tag("dialback", { xmlns='urn:xmpp:features:dialback' }):tag("optional"):up():up()); 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 not session.dialback_verifying then initiate_dialback(session); else mark_connected(session); end end session.notopen = nil; end function initiate_dialback(session) -- generate dialback key session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host); session.sends2s(format("<db:result from='%s' to='%s'>%s</db:result>", session.from_host, session.to_host, session.dialback_key)); session.log("info", "sent dialback key on outgoing s2s stream"); end function generate_dialback(id, to, from) 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, 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"); mark_connected(session); return true; end function mark_connected(session) local sendq, send = session.sendq, session.sends2s; local from, to = session.from_host, session.to_host; session.log("debug", session.direction.." s2s connection "..from.."->"..to.." is now complete"); local send_to_host = send_to_host; function session.send(data) send_to_host(to, from, data); end if session.direction == "outgoing" then 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[1]); sendq[i] = nil; end session.sendq = nil; end end end function destroy_session(session) (session.log or log)("info", "Destroying "..tostring(session.direction).." session "..tostring(session.from_host).."->"..tostring(session.to_host)); 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 if k ~= "trace" then session[k] = nil; end end end return _M;