s2smanager, mod_s2s, mod_s2s/s2sout: Split connection handling out of s2smanager into mod_s2s, and further split connection logic for s2sout to a module lib, s2sout.lib.lua

1 files changed, 11 insertions, 570 deletions

diff --git a/core/s2smanager.lua b/core/s2smanager.lua
index f44921c3..e61aaccb 100644
--- a/core/s2smanager.lua
+++ b/core/s2smanager.lua
@@ -9,18 +9,13 @@
 
 
 local hosts = hosts;
-local sessions = sessions;
 local core_process_stanza = function(a, b) core_process_stanza(a, b); end
-local add_task = require "util.timer".add_task;
-local socket = require "socket";
 local format = string.format;
 local t_insert, t_sort = table.insert, table.sort;
 local get_traceback = debug.traceback;
 local tostring, pairs, ipairs, getmetatable, newproxy, type, error, tonumber, setmetatable
     = tostring, pairs, ipairs, getmetatable, newproxy, type, error, tonumber, setmetatable;
 
-local idna_to_ascii = require "util.encodings".idna.to_ascii;
-local connlisteners_get = require "net.connlisteners".get;
 local initialize_filters = require "util.filters".initialize;
 local wrapclient = require "net.server".wrapclient;
 local st = require "stanza";
@@ -41,11 +36,13 @@ local sha256_hash = require "util.hashes".sha256;
 
 local adns, dns = require "net.adns", require "net.dns";
 local config = require "core.configmanager";
-local connect_timeout = config.get("*", "core", "s2s_timeout") or 60;
 local dns_timeout = config.get("*", "core", "dns_timeout") or 15;
 local max_dns_depth = config.get("*", "core", "dns_max_depth") or 3;
+local cfg_sources = config.get("*", "core", "s2s_interface")
+	or config.get("*", "core", "interface");
 local sources;
 
+--FIXME: s2sout should create its own resolver w/ timeout
 dns.settimeout(dns_timeout);
 
 local prosody = _G.prosody;
@@ -55,89 +52,6 @@ local incoming_s2s = incoming_s2s;
 
 module "s2smanager"
 
-function compare_srv_priorities(a,b)
-	return a.priority < b.priority or (a.priority == b.priority and a.weight > b.weight);
-end
-
-local bouncy_stanzas = { message = true, presence = true, iq = true };
-local function bounce_sendq(session, reason)
-	local sendq = session.sendq;
-	if sendq then
-		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", get_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
-end
-
-function send_to_host(from_host, to_host, data)
-	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
-	local host = hosts[from_host].s2sout[to_host];
-	if host then
-		-- We have a connection to this host already
-		if host.type == "s2sout_unauthed" and (data.name ~= "db:verify" 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(data), data.attr.type ~= "error" and data.attr.type ~= "result" and st.reply(data)});
-			else host.sendq = { {tostring(data), data.attr.type ~= "error" and data.attr.type ~= "result" and st.reply(data)} }; end
-			host.log("debug", "stanza [%s] queued ", data.name);
-		elseif host.type == "local" or host.type == "component" then
-			log("error", "Trying to send a stanza to ourselves??")
-			log("error", "Traceback: %s", get_traceback());
-			log("error", "Stanza: %s", tostring(data));
-			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
-			host.sends2s(data);
-			host.log("debug", "stanza sent over "..host.type);
-		end
-	else
-		log("debug", "opening a new outgoing connection for this stanza");
-		local host_session = new_outgoing(from_host, to_host);
-
-		-- Store in buffer
-		host_session.sendq = { {tostring(data), data.attr.type ~= "error" and data.attr.type ~= "result" and st.reply(data)} };
-		log("debug", "stanza [%s] queued until connection complete", tostring(data.name));
-		if (not host_session.connecting) and (not host_session.conn) then
-			log("warn", "Connection to %s failed already, destroying session...", to_host);
-			if not destroy_session(host_session, "Connection failed") then
-				-- Already destroyed, we need to bounce our stanza
-				bounce_sendq(host_session, host_session.destruction_reason);
-			end
-			return false;
-		end
-	end
-	return true;
-end
-
 local open_sessions = 0;
 
 function new_incoming(conn)
@@ -147,491 +61,18 @@ function new_incoming(conn)
 		getmetatable(session.trace).__gc = function () open_sessions = open_sessions - 1; end;
 	end
 	open_sessions = open_sessions + 1;
-	local w, log = conn.write, logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$"));
-	session.log = log;
-	local filter = initialize_filters(session);
-	session.sends2s = function (t)
-		log("debug", "sending: %s", t.top_tag and t:top_tag() or t:match("^([^>]*>?)"));
-		if t.name then
-			t = filter("stanzas/out", t);
-		end
-		if t then
-			t = filter("bytes/out", tostring(t));
-			if t then
-				return w(conn, t);
-			end
-		end
-	end
+	session.log = logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$"));
 	incoming_s2s[session] = true;
-	add_task(connect_timeout, function ()
-		if session.conn ~= conn or
-		   session.type == "s2sin" then
-			return; -- Ok, we're connect[ed|ing]
-		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);
 	return session;
 end
 
 function new_outgoing(from_host, to_host, connect)
-		local host_session = { to_host = to_host, from_host = from_host, host = from_host,
-		                       notopen = true, type = "s2sout_unauthed", direction = "outgoing",
-		                       open_stream = session_open_stream };
-		
-		hosts[from_host].s2sout[to_host] = host_session;
-		
-		host_session.close = destroy_session; -- This gets replaced by xmppserver_listener later
-		
-		local log;
-		do
-			local conn_name = "s2sout"..tostring(host_session):match("[a-f0-9]*$");
-			log = logger_init(conn_name);
-			host_session.log = log;
-		end
-		
-		initialize_filters(host_session);
-		
-		if connect ~= false then
-			-- Kick the connection attempting machine into life
-			if not attempt_connection(host_session) then
-				-- Intentionally not returning here, the
-				-- session is needed, connected or not
-				destroy_session(host_session);
-			end
-		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", to_host);
-				buffer[#buffer+1] = data;
-				log("debug", "Buffered item %d: %s", #buffer, tostring(data));
-			end
-		end
-
-		return host_session;
-end
-
-
-function 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 then
-				log("debug", to_host.." has SRV records, handling...");
-				local srv_hosts = {};
-				host_session.srv_hosts = srv_hosts;
-				for _, record in ipairs(answer) do
-					t_insert(srv_hosts, record.srv);
-				end
-				if #srv_hosts == 1 and srv_hosts[1].target == "." then
-					log("debug", to_host.." does not provide a XMPP service");
-					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", to_host.." has no SRV records, falling back to A");
-			end
-			-- Try with SRV, or just the plain hostname if no SRV
-			local ok, err = try_connect(host_session, connect_host, connect_port);
-			if not ok then
-				if not attempt_connection(host_session, err) then
-					-- No more attempts will be made
-					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 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 try_connect(host_session, connect_host, connect_port);
-end
-
-function 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= make_connect(host_session, ip.ip, ip.port);
-	if not ok then
-		if not attempt_connection(host_session, err or "closed") then
-			err = err and (": "..err) or "";
-			destroy_session(host_session, "Connection failed"..err);
-		end
-	end
-end
-
-function 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 has_other = false;
-
-		if not sources then
-			sources =  {};
-			local cfg_sources = config.get("*", "core", "interface") or connlisteners_get("xmppserver").default_interface;
-			if type(cfg_sources) == "string" then
-				cfg_sources = { cfg_sources };
-			end
-			for i, source in ipairs(cfg_sources) do
-				if source == "*" then
-					sources[i] = new_ip("0.0.0.0", "IPv4");
-				else
-					sources[i] = new_ip(source, (source:find(":") and "IPv6") or "IPv4");
-				end
-			end
-		end
-
-		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 has_other then
-				if #IPs > 0 then
-					rfc3484_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;
-					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 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 "";
-						destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
-					end
-				end
-			else
-				has_other = true;
-			end
-		end, connect_host, "A", "IN");
-
-		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 has_other then
-				if #IPs > 0 then
-					rfc3484_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;
-					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 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 "";
-						destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
-					end
-				end
-			else
-				has_other = true;
-			end
-		end, connect_host, "AAAA", "IN");
-
-		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
-		try_next_ip(host_session);
-	else
-		host_session.ip_hosts = nil;
-		if not 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 "";
-			destroy_session(host_session, "Connecting failed"..err); -- End of the line, we can't
-			return false;
-		end
-	end
-
-	return true;
-end
-
-function 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;
-	
-	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
-	
-	local cl = connlisteners_get("xmppserver");
-	conn = wrapclient(conn, connect_host.addr, connect_port, cl, cl.default_mode or 1 );
-	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
-	cl.register_outgoing(conn, host_session);
-	
-	host_session:open_stream(from_host, to_host);
-	
-	log("debug", "Connection attempt in progress...");
-	add_task(connect_timeout, function ()
-		if host_session.conn ~= conn or
-		   host_session.type == "s2sout" or
-		   host_session.connecting then
-			return; -- Ok, we're connect[ed|ing]
-		end
-		-- Not connected, need to close session and clean up
-		(host_session.log or log)("warn", "Destroying incomplete session %s->%s due to inactivity",
-		    host_session.from_host or "(unknown)", host_session.to_host or "(unknown)");
-		host_session:close("connection-timeout");
-	end);
-	return true;
-end
-
-function session_open_stream(session, from, to)
-	session.sends2s(st.stanza("stream:stream", {
-		xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
-		["xmlns:stream"]='http://etherx.jabber.org/streams',
-		from=from, to=to, version='1.0', ["xml:lang"]='en'}):top_tag());
-end
-
-local function check_cert_status(session)
-	local conn = session.conn:socket()
-	local cert
-	if conn.getpeercertificate then
-		cert = conn:getpeercertificate()
-	end
-
-	if cert then
-		local chain_valid, errors = conn:getpeerverification()
-		-- 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");
-			session.cert_chain_status = "invalid";
-		else
-			(session.log or log)("debug", "certificate chain validation result: valid");
-			session.cert_chain_status = "valid";
-
-			local host = session.direction == "incoming" and session.from_host or session.to_host
-
-			-- 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
-end
-
-function streamopened(session, attr)
-	local send = session.sends2s;
-	
-	-- TODO: #29: SASL/TLS on s2s streams
-	session.version = tonumber(attr.version) or 0;
-	
-	-- TODO: Rename session.secure to session.encrypted
-	if session.secure == false then
-		session.secure = true;
-	end
-
-	if session.direction == "incoming" then
-		-- Send a reply stream header
-		session.to_host = attr.to and nameprep(attr.to);
-		session.from_host = attr.from and nameprep(attr.from);
-	
-		session.streamid = uuid_gen();
-		(session.log or log)("debug", "Incoming s2s received <stream:stream>");
-		if session.to_host then
-			if not hosts[session.to_host] then
-				-- Attempting to connect to a host we don't serve
-				session:close({
-					condition = "host-unknown";
-					text = "This host does not serve "..session.to_host
-				});
-				return;
-			elseif hosts[session.to_host].disallow_s2s then
-				-- Attempting to connect to a host that disallows s2s
-				session:close({
-					condition = "policy-violation";
-					text = "Server-to-server communication is not allowed to this host";
-				});
-				return;
-			end
-		end
-
-		if session.secure and not session.cert_chain_status then check_cert_status(session); end
-
-		send("<?xml version='1.0'?>");
-		send(stanza("stream:stream", { xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
-				["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.to_host, to=session.from_host, version=(session.version > 0 and "1.0" or nil) }):top_tag());
-		if session.version >= 1.0 then
-			local features = st.stanza("stream:features");
-			
-			if session.to_host then
-				hosts[session.to_host].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", session.from_host 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 check_cert_status(session); 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
-				log("debug", "Initiating dialback...");
-				initiate_dialback(session);
-			else
-				mark_connected(session);
-			end
-		end
-	end
-	session.notopen = nil;
-end
-
-function streamclosed(session)
-	(session.log or log)("debug", "Received </stream:stream>");
-	session:close();
-end
-
-function initiate_dialback(session)
-	-- generate dialback key
-	session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
-	session.sends2s(format("<db:result from='%s' to='%s'>%s</db:result>", session.from_host, session.to_host, session.dialback_key));
-	session.log("info", "sent dialback key on outgoing s2s stream");
-end
-
-function generate_dialback(id, to, from)
-	return sha256_hash(id..to..from..hosts[from].dialback_secret, true);
-end
-
-function verify_dialback(id, to, from, key)
-	return key == generate_dialback(id, to, from);
+	local host_session = { to_host = to_host, from_host = from_host, host = from_host,
+		               notopen = true, type = "s2sout_unauthed", direction = "outgoing" };
+	hosts[from_host].s2sout[to_host] = host_session;
+	local conn_name = "s2sout"..tostring(host_session):match("[a-f0-9]*$");
+	host_session.log = logger_init(conn_name);
+	return host_session;
 end
 
 function make_authenticated(session, host)
@@ -733,7 +174,7 @@ function destroy_session(session, reason)
 	
 	if session.direction == "outgoing" then
 		hosts[session.from_host].s2sout[session.to_host] = nil;
-		bounce_sendq(session, reason);
+		session:bounce_sendq(reason);
 	elseif session.direction == "incoming" then
 		incoming_s2s[session] = nil;
 	end