Merge 0.11->trunk

2 files changed, 159 insertions, 465 deletions

diff --git a/plugins/mod_s2s/mod_s2s.lua b/plugins/mod_s2s/mod_s2s.lua
index aae37b7f..00d8f5d9 100644
--- a/plugins/mod_s2s/mod_s2s.lua
+++ b/plugins/mod_s2s/mod_s2s.lua
@@ -27,8 +27,10 @@ local s2s_destroy_session = require "core.s2smanager".destroy_session;
 local uuid_gen = require "util.uuid".generate;
 local fire_global_event = prosody.events.fire_event;
 local runner = require "util.async".runner;
-
-local s2sout = module:require("s2sout");
+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);
@@ -45,6 +47,8 @@ local sessions = module:shared("sessions");
 
 local runner_callbacks = {};
 
+local listener = {};
+
 local log = module._log;
 
 module:hook("stats-update", function ()
@@ -77,15 +81,28 @@ local function bounce_sendq(session, reason)
 			(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 = "cancel", by = session.from_host})
-				:tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
-			if reason then
+			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):up();
+					:text("Server-to-server connection failed: "..reason_text):up();
 			end
 			core_process_stanza(dummy, reply);
 		end
@@ -106,38 +123,33 @@ function route_to_existing_session(event)
 		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
-			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", tostring(stanza));
-			return false;
+	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
-			-- 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", host.from_host, from_host);
-			end
-			if host.sends2s(stanza) then
-				return true;
-			end
+			-- 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
@@ -147,17 +159,13 @@ 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", 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
+	log("debug", "stanza [%s] queued until connection complete", stanza.name);
+	connect(service.new(to_host, "xmpp-server", "tcp", { default_port = 5269 }), listener, nil, { session = host_session });
 	return true;
 end
 
@@ -182,10 +190,20 @@ function module.add_host(module)
 			-- 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();
-			return false;
+			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);
 end
@@ -203,7 +221,18 @@ function mark_connected(session)
 	if session.type == "s2sout" then
 		fire_global_event("s2sout-established", event_data);
 		hosts[from].events.fire_event("s2sout-established", event_data);
+
+		if session.incoming then
+			session.send = function(stanza)
+				return hosts[from].events.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 });
@@ -223,13 +252,6 @@ function mark_connected(session)
 			end
 			session.sendq = nil;
 		end
-
-		if session.resolver then
-			session.resolver._resolver:closeall()
-		end
-		session.resolver = nil;
-		session.ip_hosts = nil;
-		session.srv_hosts = nil;
 	end
 end
 
@@ -241,7 +263,7 @@ function make_authenticated(event)
 				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
@@ -251,15 +273,13 @@ function make_authenticated(event)
 		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
+	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;
-	else
-		return false;
 	end
 	session.log("debug", "connection %s->%s is now authenticated for %s", session.from_host, session.to_host, host);
 
@@ -301,6 +321,7 @@ 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
@@ -314,7 +335,6 @@ function stream_callbacks._streamopened(session, attr)
 			session.compressed = info.compression;
 		else
 			(session.log or log)("info", "Stream encrypted");
-			session.compressed = sock.compression and sock:compression(); --COMPAT mw/luasec-hg
 		end
 	end
 
@@ -322,7 +342,9 @@ function stream_callbacks._streamopened(session, attr)
 		-- Send a reply stream header
 
 		-- Validate to/from
-		local to, from = nameprep(attr.to), nameprep(attr.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;
@@ -416,20 +438,6 @@ function stream_callbacks._streamopened(session, attr)
 			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
@@ -471,11 +479,9 @@ function stream_callbacks.error(session, error, data)
 	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 function session_close(session, reason, remote_reason, bounce_reason)
 	local log = session.log or log;
 	if session.conn then
 		if session.notopen then
@@ -486,28 +492,24 @@ local function session_close(session, reason, remote_reason)
 			end
 		end
 		if reason then -- nil == no err, initiated by us, false == initiated by remote
+			local stream_error;
 			if type(reason) == "string" then -- assume stream error
-				log("debug", "Disconnecting %s[%s], <stream:error> is: %s", session.host or session.ip 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 session.ip or "(unknown host)", session.type, 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, reason);
-					session.sends2s(reason);
+				stream_error = st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' });
+			elseif type(reason) == "table" and not st.is_stanza(reason) then
+				stream_error = st.stanza("stream:error"):tag(reason.condition or "undefined-condition", stream_xmlns_attr):up();
+				if reason.text then
+					stream_error:tag("text", stream_xmlns_attr):text(reason.text):up();
+				end
+				if reason.extra then
+					stream_error:add_child(reason.extra);
 				end
 			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
 		end
 
 		session.sends2s("</stream:stream>");
@@ -521,16 +523,16 @@ local function session_close(session, reason, remote_reason)
 
 		-- 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
+		if reason == nil and not session.notopen and session.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);
+					s2s_destroy_session(session, reason, bounce_reason);
 					conn:close();
 				end
 			end);
 		else
-			s2s_destroy_session(session, reason);
+			s2s_destroy_session(session, reason, bounce_reason);
 			conn:close(); -- Close immediately, as this is an outgoing connection or is not authed
 		end
 	end
@@ -595,9 +597,8 @@ local function initialize_session(session)
 		if data then
 			local ok, err = stream:feed(data);
 			if ok then return; end
-			log("warn", "Received invalid XML: %s", data);
-			log("warn", "Problem was: %s", err);
-			session:close("not-well-formed");
+			log("debug", "Received invalid XML (%s) %d bytes: %q", err, #data, data:sub(1, 300));
+			session:close("not-well-formed", nil, "Received invalid XML from remote server");
 		end
 	end
 
@@ -672,11 +673,20 @@ 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);
-			if s2sout.attempt_connection(session, err) then
-				return; -- Session lives for now
-			end
 		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);
@@ -700,6 +710,34 @@ 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;
@@ -711,20 +749,21 @@ function check_auth_policy(event)
 	end
 
 	if must_secure and (session.cert_chain_status ~= "valid" or session.cert_identity_status ~= "valid") then
-		module:log("warn", "Forbidding insecure connection to/from %s", host or session.ip or "(unknown 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
+		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);
 
-s2sout.set_listener(listener);
-
 module:hook("server-stopping", function(event)
 	local reason = event.reason;
 	for _, session in pairs(sessions) do
@@ -739,7 +778,11 @@ module:provides("net", {
 	listener = listener;
 	default_port = 5269;
 	encryption = "starttls";
+	ssl_config = { -- FIXME This is not used atm, see mod_tls
+		verify = { "peer", "client_once", };
+	};
 	multiplex = {
+		protocol = "xmpp-server";
 		pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:server%1.*>";
 	};
 });
diff --git a/plugins/mod_s2s/s2sout.lib.lua b/plugins/mod_s2s/s2sout.lib.lua
deleted file mode 100644
index 5f765da8..00000000
--- a/plugins/mod_s2s/s2sout.lib.lua
+++ /dev/null
@@ -1,349 +0,0 @@
--- 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
-
--- luacheck: ignore 432/err
-
-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 t_insert, t_sort, ipairs = table.insert, table.sort, ipairs;
-local local_addresses = require "util.net".local_addresses;
-
-local s2s_destroy_session = require "core.s2smanager".destroy_session;
-
-local default_mode = module:get_option("network_default_read_size", 4096);
-
-local log = module._log;
-
-local sources = {};
-local has_ipv4, has_ipv6;
-
-local dns_timeout = module:get_option_number("dns_timeout", 15);
-local resolvers = module:get_option_set("s2s_dns_resolvers")
-
-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)
-	local log = host_session.log or log;
-
-	initialize_filters(host_session);
-	host_session.version = 1;
-
-	host_session.resolver = adns.resolver();
-	host_session.resolver._resolver:settimeout(dns_timeout);
-	if resolvers then
-		for resolver in resolvers do
-			host_session.resolver._resolver:addnameserver(resolver);
-		end
-	end
-
-	-- 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", host_session.to_host);
-			buffer[#buffer+1] = data;
-			log("debug", "Buffered item %d: %s", #buffer, data);
-		end
-	end
-end
-
-function s2sout.attempt_connection(host_session, err)
-	local to_host = host_session.to_host;
-	local connect_host, connect_port = to_host and idna_to_ascii(to_host), 5269;
-	local log = host_session.log or log;
-
-	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;
-		host_session.resolver:lookup(function (answer)
-			local srv_hosts = { answer = answer };
-			host_session.srv_hosts = srv_hosts;
-			host_session.srv_choice = 0;
-			host_session.connecting = nil;
-			if answer and #answer > 0 then
-				log("debug", "%s has SRV records, handling...", to_host);
-				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", err, host_session.srv_choice, connect_host, connect_port);
-	else
-		host_session.log("info", "Failed in all attempts to connect to %s", 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 :(", connect_host, connect_port, 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;
-	local log = host_session.log or log;
-
-	if not err then
-		local IPs = {};
-		host_session.ip_hosts = IPs;
-		-- luacheck: ignore 231/handle4 231/handle6
-		local handle4, handle6;
-		local have_other_result = not(has_ipv4) or not(has_ipv6) or false;
-
-		if has_ipv4 then
-			handle4 = host_session.resolver:lookup(function (reply, err)
-				handle4 = nil;
-
-				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
-				elseif err then
-					log("debug", "Error in DNS lookup: %s", err);
-				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 = host_session.resolver: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
-				elseif err then
-					log("debug", "Error in DNS lookup: %s", err);
-				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
-		log("debug", "Out of IP addresses, trying next SRV record (if any)");
-		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)
-	local log = host_session.log or log;
-	log("debug", "Beginning new connection attempt to %s ([%s]:%d)", host_session.to_host, connect_host.addr, connect_port);
-
-	-- Reset secure flag in case this is another
-	-- connection attempt after a failed STARTTLS
-	host_session.secure = nil;
-	host_session.encrypted = nil;
-
-	local conn, handler;
-	local proto = connect_host.proto;
-	if proto == "IPv4" then
-		conn, handler = socket.tcp();
-	elseif proto == "IPv6" and socket.tcp6 then
-		conn, handler = socket.tcp6();
-	else
-		handler = "Unsupported protocol: "..tostring(proto);
-	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, default_mode);
-	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
-	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
-			for _, addr in ipairs(local_addresses("ipv4", true)) do
-				sources[#sources + 1] = new_ip(addr, "IPv4");
-			end
-		elseif source == "::" then
-			for _, addr in ipairs(local_addresses("ipv6", true)) do
-				sources[#sources + 1] = new_ip(addr, "IPv6");
-			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
-	if not (has_ipv4 or has_ipv6)  then
-		module:log("warn", "No local IPv4 or IPv6 addresses detected, outgoing connections may fail");
-	end
-end);
-
-return s2sout;