diff options
Diffstat (limited to 'plugins/mod_s2s.lua')
| -rw-r--r-- | plugins/mod_s2s.lua | 957 |
1 files changed, 957 insertions, 0 deletions
diff --git a/plugins/mod_s2s.lua b/plugins/mod_s2s.lua new file mode 100644 index 00000000..d800138f --- /dev/null +++ b/plugins/mod_s2s.lua @@ -0,0 +1,957 @@ +-- 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 traceback = debug.traceback; + +local add_task = require "util.timer".add_task; +local stop_timer = require "util.timer".stop; +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 runner = require "util.async".runner; +local connect = require "net.connect".connect; +local service = require "net.resolvers.service"; +local errors = require "util.error"; +local set = require "util.set"; + +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", false); +local stanza_size_limit = module:get_option_number("s2s_stanza_size_limit", 1024*512); + +local measure_connections_inbound = module:metric( + "gauge", "connections_inbound", "", + "Established incoming s2s connections", + {"host", "type", "ip_family"} +); +local measure_connections_outbound = module:metric( + "gauge", "connections_outbound", "", + "Established outgoing s2s connections", + {"host", "type", "ip_family"} +); + +local m_accepted_tcp_connections = module:metric( + "counter", "accepted_tcp", "", + "Accepted incoming connections on the TCP layer" +); +local m_authn_connections = module:metric( + "counter", "authenticated", "", + "Authenticated incoming connections", + {"host", "direction", "mechanism"} +); +local m_initiated_connections = module:metric( + "counter", "initiated", "", + "Initiated outbound connections", + {"host"} +); +local m_closed_connections = module:metric( + "counter", "closed", "", + "Closed connections", + {"host", "direction", "error"} +); +local m_tls_params = module:metric( + "counter", "encrypted", "", + "Encrypted connections", + {"protocol"; "cipher"} +); + +local sessions = module:shared("sessions"); + +local runner_callbacks = {}; + +local listener = {}; + +local log = module._log; + +local s2s_service_options = { + default_port = 5269; + use_ipv4 = module:get_option_boolean("use_ipv4", true); + use_ipv6 = module:get_option_boolean("use_ipv6", true); + use_dane = module:get_option_boolean("use_dane", false); +}; +local s2s_service_options_mt = { __index = s2s_service_options } + +module:hook("stats-update", function () + measure_connections_inbound:clear() + measure_connections_outbound:clear() + -- TODO: init all expected metrics once? + -- or maybe create/delete them in host-activate/host-deactivate? requires + -- extra API in openmetrics.lua tho + for _, session in pairs(sessions) do + local is_inbound = string.sub(session.type, 4, 5) == "in" + local metric_family = is_inbound and measure_connections_inbound or measure_connections_outbound + local host = is_inbound and session.to_host or session.from_host or "" + local type_ = session.type or "other" + + -- we want to expose both v4 and v6 counters in all cases to make + -- queries smoother + local is_ipv6 = session.ip and session.ip:match(":") and 1 or 0 + local is_ipv4 = 1 - is_ipv6 + metric_family:with_labels(host, type_, "ipv4"):add(is_ipv4) + metric_family:with_labels(host, type_, "ipv6"):add(is_ipv6) + end +end); + +--- 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 %d queued stanzas because of failed outgoing connection to %s", #sendq, session.to_host); + local dummy = { + type = "s2sin"; + send = function () + (session.log or log)("error", "Replying to to an s2s error reply, please report this! Traceback: %s", traceback()); + end; + dummy = true; + close = function () + (session.log or log)("error", "Attempting to close the dummy origin of s2s error replies, please report this! Traceback: %s", traceback()); + end; + }; + -- FIXME Allow for more specific error conditions + -- TODO use util.error ? + local error_type = "cancel"; + local condition = "remote-server-not-found"; + local reason_text; + if session.had_stream then -- set when a stream is opened by the remote + error_type, condition = "wait", "remote-server-timeout"; + end + if errors.is_err(reason) then + error_type, condition, reason_text = reason.type, reason.condition, reason.text; + elseif type(reason) == "string" then + reason_text = reason; + end + 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 = error_type, by = session.from_host}) + :tag(condition, {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up(); + if reason_text then + reply:tag("text", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}) + :text("Server-to-server connection failed: "..reason_text):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 not host then return end + + -- 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 + local queued_item = { + tostring(stanza), + stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza); + }; + if host.sendq then + t_insert(host.sendq, queued_item); + else + -- luacheck: ignore 122 + host.sendq = { queued_item }; + 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", stanza); + return false; + else + if host.sends2s(stanza) then + return true; + 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); + host_session.version = 1; + + -- 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", stanza.name); + -- FIXME Cleaner solution to passing extra data from resolvers to net.server + -- This mt-clone allows resolvers to add extra data, currently used for DANE TLSA records + local extra = setmetatable({}, s2s_service_options_mt); + connect(service.new(to_host, "xmpp-server", "tcp", extra), listener, nil, { session = host_session }); + m_initiated_connections:with_labels(from_host):add(1) + return true; +end + +local function keepalive(event) + local session = event.session; + if not session.notopen then + return event.session.sends2s(' '); + end +end + +module:hook("s2s-read-timeout", keepalive, -1); + +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 https://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); + module:hook("s2s-read-timeout", keepalive, -1); + module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza) -- luacheck: ignore 212/stanza + if session.type == "s2sout" then + -- Stream is authenticated and we are seem to be done with feature negotiation, + -- so the stream is ready for stanzas. RFC 6120 Section 4.3 + mark_connected(session); + return true; + elseif require_encryption and not session.secure then + session.log("warn", "Encrypted server-to-server communication is required but was not offered by %s", session.to_host); + session:close({ + condition = "policy-violation", + text = "Encrypted server-to-server communication is required but was not offered", + }, nil, "Could not establish encrypted connection to remote server"); + return true; + elseif not session.dialback_verifying then + session.log("warn", "No SASL EXTERNAL offer and Dialback doesn't seem to be enabled, giving up"); + session:close({ + condition = "unsupported-feature", + text = "No viable authentication method offered", + }, nil, "No viable authentication method offered by remote server"); + return true; + end + end, -1); + + function module.unload() + if module.reloading then return end + for _, session in pairs(sessions) do + if session.to_host == module.host or session.from_host == module.host then + session:close("host-gone"); + end + end + end +end + +-- Stream is authorised, and ready for normal stanzas +function mark_connected(session) + + local sendq = session.sendq; + + local from, to = session.from_host, session.to_host; + + session.log("info", "%s s2s connection %s->%s complete", session.direction:gsub("^.", string.upper), from, to); + + local event_data = { session = session }; + if session.type == "s2sout" then + module:fire_event("s2sout-established", event_data); + module:context(from):fire_event("s2sout-established", event_data); + + if session.incoming then + session.send = function(stanza) + return module:context(from):fire_event("route/remote", { from_host = from, to_host = to, stanza = stanza }); + end; + end + + else + if session.outgoing and not hosts[to].s2sout[from] then + session.log("debug", "Setting up to handle route from %s to %s", to, from); + hosts[to].s2sout[from] = session; -- luacheck: ignore 122 + end + 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; + + module:fire_event("s2sin-established", event_data); + module:context(to):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); + local send = session.sends2s; + for i, data in ipairs(sendq) do + send(data[1]); + sendq[i] = nil; + end + session.sendq = nil; + end + end + + if session.connect_timeout then + stop_timer(session.connect_timeout); + session.connect_timeout = 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 and not(insecure_domains[host])) 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") + }, nil, "Could not establish encrypted connection to remote server"); + 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"; + elseif session.type ~= "s2sin" and session.type ~= "s2sout" then + return false; + end + + if session.incoming and host then + if not session.hosts[host] then session.hosts[host] = {}; end + session.hosts[host].authed = true; + end + session.log("debug", "connection %s->%s is now authenticated for %s", session.from_host, session.to_host, host); + + local local_host = session.direction == "incoming" and session.to_host or session.from_host + m_authn_connections:with_labels(local_host, session.direction, event.mechanism or "other"):add(1) + + if (session.type == "s2sout" and session.external_auth ~= "succeeded") or session.type == "s2sin" then + -- Stream either used dialback for authentication or is an incoming stream. + mark_connected(session); + end + + 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 + + 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" }; + +function stream_callbacks.handlestanza(session, stanza) + stanza = session.filter("stanzas/in", stanza); + session.thread:run(stanza); +end + +local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams"; + +function stream_callbacks.streamopened(session, attr) + -- run _streamopened in async context + session.thread:run({ stream = "opened", attr = attr }); +end + +function stream_callbacks._streamopened(session, attr) + session.version = tonumber(attr.version) or 0; + session.had_stream = true; -- Had a stream opened at least once + + -- TODO: Rename session.secure to session.encrypted + if session.secure == false then + session.secure = true; + session.encrypted = true; + + local sock = session.conn:socket(); + local info = sock.info and sock:info(); + if type(info) == "table" then + (session.log or log)("info", "Stream encrypted (%s with %s)", info.protocol, info.cipher); + session.compressed = info.compression; + m_tls_params:with_labels(info.protocol, info.cipher):add(1) + else + (session.log or log)("info", "Stream encrypted"); + end + end + + if session.direction == "incoming" then + -- Send a reply stream header + + -- Validate to/from + local to, from = attr.to, attr.from; + if to then to = nameprep(attr.to); end + if from then from = nameprep(attr.from); end + 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.destroyed then + -- sending the stream opening could have failed during an opportunistic write + return + end + + session.notopen = nil; + if session.version >= 1.0 then + local features = st.stanza("stream:features"); + + if to then + module:context(to):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 session.ip or "unknown host"); + module:fire_event("s2s-stream-features-legacy", { origin = session, features = features }); + end + + if ( session.type == "s2sin" or session.type == "s2sout" ) or features.tags[1] then + log("debug", "Sending stream features: %s", features); + session.sends2s(features); + else + (session.log or log)("warn", "No stream features to offer, giving up"); + session:close({ condition = "undefined-condition", text = "No stream features to offer" }); + end + end + elseif session.direction == "outgoing" then + session.notopen = nil; + if not attr.id then + log("warn", "Stream response did not give us a stream id!"); + session:close({ condition = "undefined-condition", text = "Missing stream ID" }); + return; + 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 + + -- 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 + module:context(session.from_host):fire_event("s2sout-authenticate-legacy", { origin = session }); + else + mark_connected(session); + end + end + end +end + +function stream_callbacks._streamclosed(session) + (session.log or log)("debug", "Received </stream:stream>"); + session:close(false); +end + +function stream_callbacks.streamclosed(session, attr) + -- run _streamclosed in async context + session.thread:run({ stream = "closed", attr = attr }); +end + +-- Some stream conditions indicate a problem on our end, e.g. that we sent +-- something invalid. Those should be investigated. Others are problems or +-- events in the remote host that don't affect us, or simply that the +-- connection was closed for being idle. +local stream_condition_severity = { + ["bad-format"] = "warn"; + ["bad-namespace-prefix"] = "warn"; + ["conflict"] = "warn"; + ["connection-timeout"] = "debug"; + ["host-gone"] = "info"; + ["host-unknown"] = "info"; + ["improper-addressing"] = "warn"; + ["internal-server-error"] = "warn"; + ["invalid-from"] = "warn"; + ["invalid-namespace"] = "warn"; + ["invalid-xml"] = "warn"; + ["not-authorized"] = "warn"; + ["not-well-formed"] = "warn"; + ["policy-violation"] = "warn"; + ["remote-connection-failed"] = "warn"; + ["reset"] = "info"; + ["resource-constraint"] = "info"; + ["restricted-xml"] = "warn"; + ["see-other-host"] = "info"; + ["system-shutdown"] = "info"; + ["undefined-condition"] = "warn"; + ["unsupported-encoding"] = "warn"; + ["unsupported-feature"] = "warn"; + ["unsupported-stanza-type"] = "warn"; + ["unsupported-version"] = "warn"; +} + +function stream_callbacks.error(session, error, data) + if error == "no-stream" then + session.log("debug", "Invalid opening stream header (%s)", (data:gsub("^([^\1]+)\1", "{%1}"))); + session:close("invalid-namespace"); + elseif error == "parse-error" then + session.log("debug", "Server-to-server XML parse error: %s", error); + session:close("not-well-formed"); + elseif error == "stream-error" then + local condition, text = "undefined-condition"; + for child in data:childtags(nil, xmlns_xmpp_streams) do + if child.name ~= "text" then + condition = child.name; + else + text = child:get_text(); + end + if condition ~= "undefined-condition" and text then + break; + end + end + text = condition .. (text and (" ("..text..")") or ""); + session.log(stream_condition_severity[condition] or "info", "Session closed by remote with error: %s", text); + session:close(nil, text); + end +end + +--- Session methods +local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'}; +-- reason: stream error to send to the remote server +-- remote_reason: stream error received from the remote server +-- bounce_reason: stanza error to pass to bounce_sendq because stream- and stanza errors are different +local function session_close(session, reason, remote_reason, bounce_reason) + local log = session.log or log; + if not session.conn then + log("debug", "Attempt to close without associated connection with reason %q", reason); + return + end + + local conn = session.conn; + conn:pause_writes(); -- until :close + 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 + + local this_host = session.direction == "outgoing" and session.from_host or session.to_host + + if reason then -- nil == no err, initiated by us, false == initiated by remote + local stream_error; + local condition, text, extra + if type(reason) == "string" then -- assume stream error + condition = reason + elseif type(reason) == "table" and not st.is_stanza(reason) then + condition = reason.condition or "undefined-condition" + text = reason.text + extra = reason.extra + end + if condition then + stream_error = st.stanza("stream:error"):tag(condition, stream_xmlns_attr):up(); + if text then + stream_error:tag("text", stream_xmlns_attr):text(text):up(); + end + if extra then + stream_error:add_child(extra); + end + end + if this_host and condition then + m_closed_connections:with_labels(this_host, session.direction, condition):add(1) + end + if st.is_stanza(stream_error) then + -- to and from are never unknown on outgoing connections + log("debug", "Disconnecting %s->%s[%s], <stream:error> is: %s", + session.from_host or "(unknown host)" or session.ip, session.to_host or "(unknown host)", session.type, reason); + session.sends2s(stream_error); + end + else + m_closed_connections:with_labels(this_host or ":unknown", session.direction, reason == false and ":remote-choice" or ":local-choice"):add(1) + end + + session.sends2s("</stream:stream>"); + function session.sends2s() return false; end + + -- luacheck: ignore 422/reason 412/reason + -- FIXME reason should be managed in a place common to c2s, s2s, bosh, component etc + 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:gsub("^.", string.upper), + session.from_host or "(unknown host)", session.to_host or "(unknown host)", reason or "stream closed"); + + conn:resume_writes(); + + if session.connect_timeout then + stop_timer(session.connect_timeout); + session.connect_timeout = nil; + end + + -- Authenticated incoming stream may still be sending us stanzas, so wait for </stream:stream> from remote + if reason == nil and not session.notopen and session.direction == "incoming" 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, bounce_reason); + conn:close(); + end + end); + else + s2s_destroy_session(session, reason, bounce_reason); + conn:close(); -- Close immediately, as this is an outgoing connection or is not authed + end +end + +function session_stream_attrs(session, from, to, attr) -- luacheck: ignore 212/session + if not from or (hosts[from] and hosts[from].modules.dialback) then + attr["xmlns:db"] = 'jabber:server:dialback'; + end + if not from then + attr.from = ''; + end + if not to then + attr.to = ''; + end +end + +-- Session initialization logic shared by incoming and outgoing +local function initialize_session(session) + local stream = new_xmpp_stream(session, stream_callbacks, stanza_size_limit); + + session.thread = runner(function (stanza) + if st.is_stanza(stanza) then + core_process_stanza(session, stanza); + elseif stanza.stream == "opened" then + stream_callbacks._streamopened(session, stanza.attr); + elseif stanza.stream == "closed" then + stream_callbacks._streamclosed(session, stanza.attr); + end + end, runner_callbacks, session); + + local log = session.log or log; + session.stream = stream; + + session.notopen = true; + + function session.reset_stream() + session.notopen = true; + session.streamid = nil; + session.stream:reset(); + end + + session.stream_attrs = session_stream_attrs; + + local filter = initialize_filters(session); + local conn = session.conn; + local w = conn.write; + + function session.sends2s(t) + log("debug", "Sending[%s]: %s", session.type, 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 + + function session.data(data) + data = filter("bytes/in", data); + if data then + local ok, err = stream:feed(data); + if ok then return; end + log("debug", "Received invalid XML (%s) %d bytes: %q", err, #data, data:sub(1, 300)); + if err == "stanza-too-large" then + session:close({ condition = "policy-violation", text = "XML stanza is too big" }, nil, "Received invalid XML from remote server"); + else + session:close("not-well-formed", nil, "Received invalid XML from remote server"); + end + end + end + + session.close = session_close; + + local handlestanza = stream_callbacks.handlestanza; + function session.dispatch_stanza(session, stanza) -- luacheck: ignore 432/session + return handlestanza(session, stanza); + end + + module:fire_event("s2s-created", { session = session }); + + session.connect_timeout = 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 runner_callbacks:ready() + self.data.log("debug", "Runner %s ready (%s)", self.thread, coroutine.status(self.thread)); + self.data.conn:resume(); +end + +function runner_callbacks:waiting() + self.data.log("debug", "Runner %s waiting (%s)", self.thread, coroutine.status(self.thread)); + self.data.conn:pause(); +end + +function runner_callbacks:error(err) + (self.data.log or log)("error", "Traceback[s2s]: %s", err); +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"); + initialize_session(session); + m_accepted_tcp_connections:with_labels():add(1) + else -- Outgoing session connected + session:open_stream(session.from_host, session.to_host); + end + session.ip = conn:ip(); +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; + (session.log or log)("debug", "s2s disconnected: %s->%s (%s)", session.from_host, session.to_host, err or "connection closed"); + if session.secure == false and err then + -- TODO util.error-ify this + err = "Error during negotiation of encrypted connection: "..err; + end + s2s_destroy_session(session, err); + end +end + +function listener.onfail(data, err) + local session = data and data.session; + if session then + if err and session.direction == "outgoing" and session.notopen then + (session.log or log)("debug", "s2s connection attempt failed: %s", err); + end + (session.log or log)("debug", "s2s disconnected: %s->%s (%s)", session.from_host, session.to_host, err or "connection closed"); + s2s_destroy_session(session, err); + end +end + +function listener.onreadtimeout(conn) + local session = sessions[conn]; + if session then + local host = session.host or session.to_host; + return (hosts[host] or prosody).events.fire_event("s2s-read-timeout", { session = session }); + end +end + +function listener.ondrain(conn) + local session = sessions[conn]; + if session then + return (hosts[session.host] or prosody).events.fire_event("s2s-ondrain", { session = session }); + end +end + +function listener.onpredrain(conn) + local session = sessions[conn]; + if session then + return (hosts[session.host] or prosody).events.fire_event("s2s-pre-ondrain", { session = session }); + end +end + +function listener.register_outgoing(conn, session) + sessions[conn] = session; + initialize_session(session); +end + +function listener.ondetach(conn) + sessions[conn] = nil; +end + +function listener.onattach(conn, data) + local session = data and data.session; + if session then + session.conn = conn; + sessions[conn] = session; + initialize_session(session); + end +end + +-- Complete the sentence "Your certificate " with what's wrong +local function friendly_cert_error(session) --> string + if session.cert_chain_status == "invalid" then + if session.cert_chain_errors then + local cert_errors = set.new(session.cert_chain_errors[1]); + if cert_errors:contains("certificate has expired") then + return "has expired"; + elseif cert_errors:contains("self signed certificate") then + return "is self-signed"; + end + end + return "is not trusted"; -- for some other reason + elseif session.cert_identity_status == "invalid" then + return "is not valid for this name"; + end + -- this should normally be unreachable except if no s2s auth module was loaded + return "could not be validated"; +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 (session.cert_chain_status ~= "valid" or session.cert_identity_status ~= "valid") then + local reason = friendly_cert_error(session); + session.log("warn", "Forbidding insecure connection to/from %s because its certificate %s", host or session.ip or "(unknown host)", reason); + -- XEP-0178 recommends closing outgoing connections without warning + -- but does not give a rationale for this. + -- In practice most cases are configuration mistakes or forgotten + -- certificate renewals. We think it's better to let the other party + -- know about the problem so that they can fix it. + session:close({ condition = "not-authorized", text = "Your server's certificate "..reason }, + nil, "Remote server's certificate "..reason); + return false; + end +end + +module:hook("s2s-check-certificate", check_auth_policy, -1); + +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, -200); + + + +module:provides("net", { + name = "s2s"; + listener = listener; + default_port = 5269; + encryption = "starttls"; + ssl_config = { + -- FIXME This only applies to Direct TLS, which we don't use yet. + -- This gets applied for real in mod_tls + verify = { "peer", "client_once", }; + }; + multiplex = { + protocol = "xmpp-server"; + pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:server%1.*>"; + }; +}); + |