diff options
Diffstat (limited to 'plugins/mod_s2s')
| -rw-r--r-- | plugins/mod_s2s/mod_s2s.lua | 677 | ||||
| -rw-r--r-- | plugins/mod_s2s/s2sout.lib.lua | 361 |
2 files changed, 1038 insertions, 0 deletions
diff --git a/plugins/mod_s2s/mod_s2s.lua b/plugins/mod_s2s/mod_s2s.lua new file mode 100644 index 00000000..30ebb706 --- /dev/null +++ b/plugins/mod_s2s/mod_s2s.lua @@ -0,0 +1,677 @@ +-- 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 prosody = prosody; +local hosts = prosody.hosts; +local core_process_stanza = prosody.core_process_stanza; + +local tostring, type = tostring, type; +local t_insert = table.insert; +local xpcall, traceback = xpcall, debug.traceback; +local NULL = {}; + +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 fire_global_event = prosody.events.fire_event; + +local s2sout = module:require("s2sout"); + +local connect_timeout = module:get_option_number("s2s_timeout", 90); +local stream_close_timeout = module:get_option_number("s2s_close_timeout", 5); +local opt_keepalives = module:get_option_boolean("s2s_tcp_keepalives", module:get_option_boolean("tcp_keepalives", true)); +local secure_auth = module:get_option_boolean("s2s_secure_auth", false); -- One day... +local secure_domains, insecure_domains = + module:get_option_set("s2s_secure_domains", {})._items, module:get_option_set("s2s_insecure_domains", {})._items; +local require_encryption = module:get_option_boolean("s2s_require_encryption", secure_auth); + +local sessions = module:shared("sessions"); + +local log = module._log; + +--- 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", 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 + +-- Handles stanzas to existing s2s sessions +function route_to_existing_session(event) + local from_host, to_host, stanza = event.from_host, event.to_host, event.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 + if hosts[to_host] then + log("warn", "Attempt to route stanza to a remote %s - a host we do 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); + return true; + elseif host.type == "local" or host.type == "component" then + log("error", "Trying to send a stanza to ourselves??") + log("error", "Traceback: %s", 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 + if host.sends2s(stanza) then + host.log("debug", "stanza sent over %s", host.type); + return true; + end + end + end +end + +-- Create a new outgoing session for a stanza +function route_to_new_session(event) + local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza; + 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); + s2s_destroy_session(host_session, "Connection failed"); + return false; + end + return true; +end + +function module.add_host(module) + if module:get_option_boolean("disallow_s2s", false) then + module:log("warn", "The 'disallow_s2s' config option is deprecated, please see http://prosody.im/doc/s2s#disabling"); + return nil, "This host has disallow_s2s set"; + end + module:hook("route/remote", route_to_existing_session, -1); + module:hook("route/remote", route_to_new_session, -10); + module:hook("s2s-authenticated", make_authenticated, -1); +end + +-- Stream is authorised, and ready for normal stanzas +function mark_connected(session) + local sendq, send = session.sendq, session.sends2s; + + local from, to = session.from_host, session.to_host; + + session.log("info", "%s s2s connection %s->%s complete", session.direction, from, to); + + local event_data = { session = session }; + if session.type == "s2sout" then + fire_global_event("s2sout-established", event_data); + hosts[from].events.fire_event("s2sout-established", event_data); + else + local host_session = hosts[to]; + session.send = function(stanza) + return host_session.events.fire_event("route/remote", { from_host = to, to_host = from, stanza = stanza }); + end; + + fire_global_event("s2sin-established", event_data); + hosts[to].events.fire_event("s2sin-established", event_data); + end + + if session.direction == "outgoing" then + if sendq then + session.log("debug", "sending %d queued stanzas across new outgoing connection to %s", #sendq, session.to_host); + for i, data in ipairs(sendq) do + send(data[1]); + sendq[i] = nil; + end + session.sendq = nil; + end + + session.ip_hosts = nil; + session.srv_hosts = nil; + end +end + +function make_authenticated(event) + local session, host = event.session, event.host; + if not session.secure then + if require_encryption or secure_auth or secure_domains[host] then + session:close({ + condition = "policy-violation", + text = "Encrypted server-to-server communication is required but was not " + ..((session.direction == "outgoing" and "offered") or "used") + }); + end + end + if hosts[host] then + session:close({ condition = "undefined-condition", text = "Attempt to authenticate as a host we serve" }); + end + if session.type == "s2sout_unauthed" then + session.type = "s2sout"; + elseif session.type == "s2sin_unauthed" then + session.type = "s2sin"; + if host then + if not session.hosts[host] then session.hosts[host] = {}; end + session.hosts[host].authed = true; + end + elseif session.type == "s2sin" and host then + if not session.hosts[host] then session.hosts[host] = {}; end + session.hosts[host].authed = true; + else + return false; + end + session.log("debug", "connection %s->%s is now authenticated for %s", session.from_host, session.to_host, host); + + mark_connected(session); + + return true; +end + +--- Helper to check that a session peer's certificate is valid +local function check_cert_status(session) + local host = session.direction == "outgoing" and session.to_host or session.from_host + local conn = session.conn:socket() + local cert + if conn.getpeercertificate then + cert = conn:getpeercertificate() + end + + if cert then + local chain_valid, errors; + if conn.getpeerverification then + chain_valid, errors = conn:getpeerverification(); + elseif conn.getpeerchainvalid then -- COMPAT mw/luasec-hg + chain_valid, errors = conn:getpeerchainvalid(); + errors = (not chain_valid) and { { errors } } or nil; + else + chain_valid, errors = false, { { "Chain verification not supported by this version of LuaSec" } }; + end + -- 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"); + for depth, t in ipairs(errors or NULL) do + (session.log or log)("debug", "certificate error(s) at depth %d: %s", depth-1, table.concat(t, ", ")) + end + session.cert_chain_status = "invalid"; + else + (session.log or log)("debug", "certificate chain validation result: valid"); + session.cert_chain_status = "valid"; + + -- 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 + return module:fire_event("s2s-check-certificate", { host = host, session = session, cert = cert }); +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; + + session.version = tonumber(attr.version) or 0; + + -- TODO: Rename session.secure to session.encrypted + if session.secure == false then + session.secure = true; + + -- Check if TLS compression is used + local sock = session.conn:socket(); + if sock.info then + session.compressed = sock:info"compression"; + elseif sock.compression then + session.compressed = sock:compression(); --COMPAT mw/luasec-hg + end + end + + if session.direction == "incoming" then + -- Send a reply stream header + + -- Validate to/from + local to, from = nameprep(attr.to), nameprep(attr.from); + if not to and attr.to then -- COMPAT: Some servers do not reliably set 'to' (especially on stream restarts) + session:close({ condition = "improper-addressing", text = "Invalid 'to' address" }); + return; + end + if not from and attr.from then -- COMPAT: Some servers do not reliably set 'from' (especially on stream restarts) + session:close({ condition = "improper-addressing", text = "Invalid 'from' address" }); + return; + end + + -- Set session.[from/to]_host if they have not been set already and if + -- this session isn't already authenticated + if session.type == "s2sin_unauthed" and from and not session.from_host then + session.from_host = from; + elseif from ~= session.from_host then + session:close({ condition = "improper-addressing", text = "New stream 'from' attribute does not match original" }); + return; + end + if session.type == "s2sin_unauthed" and to and not session.to_host then + session.to_host = to; + elseif to ~= session.to_host then + session:close({ condition = "improper-addressing", text = "New stream 'to' attribute does not match original" }); + return; + end + + -- For convenience we'll put the sanitised values into these variables + to, from = session.to_host, session.from_host; + + session.streamid = uuid_gen(); + (session.log or log)("debug", "Incoming s2s received %s", st.stanza("stream:stream", attr):top_tag()); + if to then + if not hosts[to] then + -- Attempting to connect to a host we don't serve + session:close({ + condition = "host-unknown"; + text = "This host does not serve "..to + }); + return; + elseif not hosts[to].modules.s2s then + -- Attempting to connect to a host that disallows s2s + session:close({ + condition = "policy-violation"; + text = "Server-to-server communication is disabled for this host"; + }); + return; + end + end + + if hosts[from] then + session:close({ condition = "undefined-condition", text = "Attempt to connect from a host we serve" }); + return; + end + + if session.secure and not session.cert_chain_status then + if check_cert_status(session) == false then + return; + end + end + + session:open_stream(session.to_host, session.from_host) + if session.version >= 1.0 then + local features = st.stanza("stream:features"); + + if to then + hosts[to].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", from 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 + if check_cert_status(session) == false then + return; + end + 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 + hosts[session.from_host].events.fire_event("s2sout-authenticate-legacy", { origin = session }); + else + mark_connected(session); + end + end + end + session.notopen = nil; +end + +function stream_callbacks.streamclosed(session) + (session.log or log)("debug", "Received </stream:stream>"); + session:close(false); +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", traceback(tostring(err), 2)); 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 = {}; + +--- Session methods +local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'}; +local function session_close(session, reason, remote_reason) + local log = session.log or log; + if session.conn then + if session.notopen then + if session.direction == "incoming" then + session:open_stream(session.to_host, session.from_host); + else + session:open_stream(session.from_host, session.to_host); + end + end + if reason then -- nil == no err, initiated by us, false == initiated by remote + if type(reason) == "string" then -- assume stream error + log("debug", "Disconnecting %s[%s], <stream:error> 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("debug", "Disconnecting %s[%s], <stream:error> is: %s", session.host or "(unknown host)", session.type, tostring(stanza)); + session.sends2s(stanza); + elseif reason.name then -- a stanza + log("debug", "Disconnecting %s->%s[%s], <stream:error> 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("</stream:stream>"); + function session.sends2s() return false; end + + local reason = remote_reason or (reason and (reason.text or reason.condition)) or reason; + session.log("info", "%s s2s stream %s->%s closed: %s", session.direction, session.from_host or "(unknown host)", session.to_host or "(unknown host)", reason or "stream closed"); + + -- Authenticated incoming stream may still be sending us stanzas, so wait for </stream:stream> from remote + local conn = session.conn; + if reason == nil and not session.notopen and session.type == "s2sin" then + add_task(stream_close_timeout, function () + if not session.destroyed then + session.log("warn", "Failed to receive a stream close response, closing connection anyway..."); + s2s_destroy_session(session, reason); + conn:close(); + end + end); + else + s2s_destroy_session(session, reason); + conn:close(); -- Close immediately, as this is an outgoing connection or is not authed + end + end +end + +function session_open_stream(session, from, to) + local attr = { + ["xmlns:stream"] = 'http://etherx.jabber.org/streams', + xmlns = 'jabber:server', + version = session.version and (session.version > 0 and "1.0" or nil), + ["xml:lang"] = 'en', + id = session.streamid, + from = from, to = to, + } + if not from or (hosts[from] and hosts[from].modules.dialback) then + attr["xmlns:db"] = 'jabber:server:dialback'; + end + + session.sends2s("<?xml version='1.0'?>"); + session.sends2s(st.stanza("stream:stream", attr):top_tag()); + return true; +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 + + session.open_stream = session_open_stream; + + 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 + + add_task(connect_timeout, function () + if session.type == "s2sin" or session.type == "s2sout" then + return; -- Ok, we're connected + elseif session.type == "s2s_destroyed" then + return; -- Session already destroyed + 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) + conn:setoption("keepalive", opt_keepalives); + local session = sessions[conn]; + if not session then -- New incoming connection + 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); + else -- Outgoing session connected + session:open_stream(session.from_host, session.to_host); + 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 + 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 + sessions[conn] = nil; + if err and session.direction == "outgoing" and session.notopen 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; -- Session lives for now + end + end + (session.log or log)("debug", "s2s disconnected: %s->%s (%s)", tostring(session.from_host), tostring(session.to_host), tostring(err or "connection closed")); + s2s_destroy_session(session, err); + end +end + +function listener.register_outgoing(conn, session) + session.direction = "outgoing"; + sessions[conn] = session; + initialize_session(session); +end + +function check_auth_policy(event) + local host, session = event.host, event.session; + local must_secure = secure_auth; + + if not must_secure and secure_domains[host] then + must_secure = true; + elseif must_secure and insecure_domains[host] then + must_secure = false; + end + + if must_secure and not session.cert_identity_status then + module:log("warn", "Forbidding insecure connection to/from %s", host); + if session.direction == "incoming" then + session:close({ condition = "not-authorized", text = "Your server's certificate is invalid, expired, or not trusted by "..session.to_host }); + else -- Close outgoing connections without warning + session:close(false); + end + return false; + end +end + +module:hook("s2s-check-certificate", check_auth_policy, -1); + +s2sout.set_listener(listener); + +module:hook("server-stopping", function(event) + local reason = event.reason; + for _, session in pairs(sessions) do + session:close{ condition = "system-shutdown", text = reason }; + end +end,500); + + + +module:provides("net", { + name = "s2s"; + listener = listener; + default_port = 5269; + encryption = "starttls"; + multiplex = { + pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:server%1.*>"; + }; +}); + diff --git a/plugins/mod_s2s/s2sout.lib.lua b/plugins/mod_s2s/s2sout.lib.lua new file mode 100644 index 00000000..cb2f8be4 --- /dev/null +++ b/plugins/mod_s2s/s2sout.lib.lua @@ -0,0 +1,361 @@ +-- 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 containing all the logic for connecting to a remote server + +local portmanager = require "core.portmanager"; +local wrapclient = require "net.server".wrapclient; +local initialize_filters = require "util.filters".initialize; +local idna_to_ascii = require "util.encodings".idna.to_ascii; +local new_ip = require "util.ip".new_ip; +local rfc6724_dest = require "util.rfc6724".destination; +local socket = require "socket"; +local adns = require "net.adns"; +local dns = require "net.dns"; +local t_insert, t_sort, ipairs = table.insert, table.sort, ipairs; +local st = require "util.stanza"; + +local s2s_destroy_session = require "core.s2smanager".destroy_session; + +local log = module._log; + +local sources = {}; +local has_ipv4, has_ipv6; + +local dns_timeout = module:get_option_number("dns_timeout", 15); +dns.settimeout(dns_timeout); +local max_dns_depth = module:get_option_number("dns_max_depth", 3); + +local s2sout = {}; + +local s2s_listener; + + +function s2sout.set_listener(listener) + s2s_listener = listener; +end + +local function compare_srv_priorities(a,b) + return a.priority < b.priority or (a.priority == b.priority and a.weight > b.weight); +end + +function s2sout.initiate_connection(host_session) + initialize_filters(host_session); + host_session.version = 1; + host_session.open_stream = session_open_stream; + + -- Kick the connection attempting machine into life + if not s2sout.attempt_connection(host_session) then + -- Intentionally not returning here, the + -- session is needed, connected or not + s2s_destroy_session(host_session); + end + + if not host_session.sends2s then + -- A sends2s which buffers data (until the stream is opened) + -- note that data in this buffer will be sent before the stream is authed + -- and will not be ack'd in any way, successful or otherwise + local buffer; + function host_session.sends2s(data) + if not buffer then + buffer = {}; + host_session.send_buffer = buffer; + end + log("debug", "Buffering data on unconnected s2sout to %s", tostring(host_session.to_host)); + buffer[#buffer+1] = data; + log("debug", "Buffered item %d: %s", #buffer, tostring(data)); + end + end +end + +function s2sout.attempt_connection(host_session, err) + local from_host, to_host = host_session.from_host, host_session.to_host; + local connect_host, connect_port = to_host and idna_to_ascii(to_host), 5269; + + if not connect_host then + return false; + end + + if not err then -- This is our first attempt + log("debug", "First attempt to connect to %s, starting with SRV lookup...", to_host); + host_session.connecting = true; + local handle; + handle = adns.lookup(function (answer) + handle = nil; + host_session.connecting = nil; + if answer and #answer > 0 then + log("debug", "%s has SRV records, handling...", to_host); + local srv_hosts = { answer = answer }; + host_session.srv_hosts = srv_hosts; + for _, record in ipairs(answer) do + t_insert(srv_hosts, record.srv); + end + if #srv_hosts == 1 and srv_hosts[1].target == "." then + log("debug", "%s does not provide a XMPP service", to_host); + s2s_destroy_session(host_session, err); -- Nothing to see here + return; + 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 + else + log("debug", "%s has no SRV records, falling back to A/AAAA", to_host); + end + -- Try with SRV, or just the plain hostname if no SRV + local ok, err = s2sout.try_connect(host_session, connect_host, connect_port); + if not ok then + if not s2sout.attempt_connection(host_session, err) then + -- No more attempts will be made + s2s_destroy_session(host_session, err); + end + end + end, "_xmpp-server._tcp."..connect_host..".", "SRV"); + + return true; -- Attempt in progress + elseif host_session.ip_hosts then + return s2sout.try_connect(host_session, connect_host, connect_port, err); + 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("info", "Connection failed (%s). Attempt #%d: This time to %s:%d", tostring(err), host_session.srv_choice, connect_host, connect_port); + else + host_session.log("info", "Out of connection options, can't connect to %s", tostring(host_session.to_host)); + -- We're out of options + return false; + end + + if not (connect_host and connect_port) then + -- Likely we couldn't resolve DNS + log("warn", "Hmm, we're without a host (%s) and port (%s) to connect to for %s, giving up :(", tostring(connect_host), tostring(connect_port), tostring(to_host)); + return false; + end + + return s2sout.try_connect(host_session, connect_host, connect_port); +end + +function s2sout.try_next_ip(host_session) + host_session.connecting = nil; + host_session.ip_choice = host_session.ip_choice + 1; + local ip = host_session.ip_hosts[host_session.ip_choice]; + local ok, err= s2sout.make_connect(host_session, ip.ip, ip.port); + if not ok then + if not s2sout.attempt_connection(host_session, err or "closed") then + err = err and (": "..err) or ""; + s2s_destroy_session(host_session, "Connection failed"..err); + end + end +end + +function s2sout.try_connect(host_session, connect_host, connect_port, err) + host_session.connecting = true; + + if not err then + local IPs = {}; + host_session.ip_hosts = IPs; + local handle4, handle6; + local have_other_result = not(has_ipv4) or not(has_ipv6) or false; + + if has_ipv4 then + handle4 = adns.lookup(function (reply, err) + handle4 = nil; + + -- COMPAT: This is a compromise for all you CNAME-(ab)users :) + if not (reply and reply[#reply] and reply[#reply].a) then + local count = max_dns_depth; + reply = dns.peek(connect_host, "CNAME", "IN"); + while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do + log("debug", "Looking up %s (DNS depth is %d)", tostring(reply[#reply].cname), count); + reply = dns.peek(reply[#reply].cname, "A", "IN") or dns.peek(reply[#reply].cname, "CNAME", "IN"); + count = count - 1; + end + end + -- end of CNAME resolving + + if reply and reply[#reply] and reply[#reply].a then + for _, ip in ipairs(reply) do + log("debug", "DNS reply for %s gives us %s", connect_host, ip.a); + IPs[#IPs+1] = new_ip(ip.a, "IPv4"); + end + end + + if have_other_result then + if #IPs > 0 then + rfc6724_dest(host_session.ip_hosts, sources); + for i = 1, #IPs do + IPs[i] = {ip = IPs[i], port = connect_port}; + end + host_session.ip_choice = 0; + s2sout.try_next_ip(host_session); + else + log("debug", "DNS lookup failed to get a response for %s", connect_host); + host_session.ip_hosts = nil; + if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can + log("debug", "No other records to try for %s - destroying", host_session.to_host); + err = err and (": "..err) or ""; + s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't + end + end + else + have_other_result = true; + end + end, connect_host, "A", "IN"); + else + have_other_result = true; + end + + if has_ipv6 then + handle6 = adns.lookup(function (reply, err) + handle6 = nil; + + if reply and reply[#reply] and reply[#reply].aaaa then + for _, ip in ipairs(reply) do + log("debug", "DNS reply for %s gives us %s", connect_host, ip.aaaa); + IPs[#IPs+1] = new_ip(ip.aaaa, "IPv6"); + end + end + + if have_other_result then + if #IPs > 0 then + rfc6724_dest(host_session.ip_hosts, sources); + for i = 1, #IPs do + IPs[i] = {ip = IPs[i], port = connect_port}; + end + host_session.ip_choice = 0; + s2sout.try_next_ip(host_session); + else + log("debug", "DNS lookup failed to get a response for %s", connect_host); + host_session.ip_hosts = nil; + if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can + log("debug", "No other records to try for %s - destroying", host_session.to_host); + err = err and (": "..err) or ""; + s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't + end + end + else + have_other_result = true; + end + end, connect_host, "AAAA", "IN"); + else + have_other_result = true; + end + return true; + elseif host_session.ip_hosts and #host_session.ip_hosts > host_session.ip_choice then -- Not our first attempt, and we also have IPs left to try + s2sout.try_next_ip(host_session); + else + host_session.ip_hosts = nil; + if not s2sout.attempt_connection(host_session, "out of IP addresses") then -- Retry if we can + log("debug", "No other records to try for %s - destroying", host_session.to_host); + err = err and (": "..err) or ""; + s2s_destroy_session(host_session, "Connecting failed"..err); -- End of the line, we can't + return false; + end + end + + return true; +end + +function s2sout.make_connect(host_session, connect_host, connect_port) + (host_session.log or log)("info", "Beginning new connection attempt to %s ([%s]:%d)", host_session.to_host, connect_host.addr, connect_port); + -- Ok, we're going to try to connect + + local from_host, to_host = host_session.from_host, host_session.to_host; + + -- Reset secure flag in case this is another + -- connection attempt after a failed STARTTLS + host_session.secure = nil; + + local conn, handler; + if connect_host.proto == "IPv4" then + conn, handler = socket.tcp(); + else + conn, handler = socket.tcp6(); + end + + if not conn then + log("warn", "Failed to create outgoing connection, system error: %s", handler); + return false, handler; + end + + conn:settimeout(0); + local success, err = conn:connect(connect_host.addr, connect_port); + if not success and err ~= "timeout" then + log("warn", "s2s connect() to %s (%s:%d) failed: %s", host_session.to_host, connect_host.addr, connect_port, err); + return false, err; + end + + conn = wrapclient(conn, connect_host.addr, connect_port, s2s_listener, "*a"); + host_session.conn = conn; + + local filter = initialize_filters(host_session); + local w, log = conn.write, host_session.log; + host_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, tostring(t)); + end + end + end + + -- Register this outgoing connection so that xmppserver_listener knows about it + -- otherwise it will assume it is a new incoming connection + s2s_listener.register_outgoing(conn, host_session); + + log("debug", "Connection attempt in progress..."); + return true; +end + +module:hook_global("service-added", function (event) + if event.name ~= "s2s" then return end + + local s2s_sources = portmanager.get_active_services():get("s2s"); + if not s2s_sources then + module:log("warn", "s2s not listening on any ports, outgoing connections may fail"); + return; + end + for source, _ in pairs(s2s_sources) do + if source == "*" or source == "0.0.0.0" then + if not socket.local_addresses then + sources[#sources + 1] = new_ip("0.0.0.0", "IPv4"); + else + for _, addr in ipairs(socket.local_addresses("ipv4", true)) do + sources[#sources + 1] = new_ip(addr, "IPv4"); + end + end + elseif source == "::" then + if not socket.local_addresses then + sources[#sources + 1] = new_ip("::", "IPv6"); + else + for _, addr in ipairs(socket.local_addresses("ipv6", true)) do + sources[#sources + 1] = new_ip(addr, "IPv6"); + end + end + else + sources[#sources + 1] = new_ip(source, (source:find(":") and "IPv6") or "IPv4"); + end + end + for i = 1,#sources do + if sources[i].proto == "IPv6" then + has_ipv6 = true; + elseif sources[i].proto == "IPv4" then + has_ipv4 = true; + end + end +end); + +return s2sout; |