--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_component_client/mod_component_client.lua	Tue Apr 30 20:46:02 2013 +0500
@@ -0,0 +1,231 @@
+--[[
+
+mod_component_client.lua
+
+This module turns Prosody hosts into components of other XMPP servers.
+
+Config:
+
+VirtualHost "component.example.com"
+	component_client = {
+		host = "localhost";
+		port = 5347;
+		secret = "hunter2";
+	}
+
+
+]]
+
+
+local socket = require "socket"
+
+local logger = require "util.logger";
+local sha1 = require "util.hashes".sha1;
+local st = require "util.stanza";
+
+local jid_split = require "util.jid".split;
+local new_xmpp_stream = require "util.xmppstream".new;
+local uuid_gen = require "util.uuid".generate;
+
+local core_process_stanza = prosody.core_process_stanza;
+local hosts = prosody.hosts;
+
+local log = module._log;
+
+local config = module:get_option("component_client", {});
+local server_host = config.host or "localhost";
+local server_port = config.port or 5347;
+local server_secret = config.secret or error("client_component.secret not provided");
+
+local __conn;
+
+local listener = {};
+local session;
+
+local xmlns_component = 'jabber:component:accept';
+local stream_callbacks = { default_ns = xmlns_component };
+
+local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
+
+function stream_callbacks.error(session, error, data, data2)
+	if session.destroyed then return; end
+	module:log("warn", "Error processing component stream: %s", tostring(error));
+	if error == "no-stream" then
+		session:close("invalid-namespace");
+	elseif error == "parse-error" then
+		session.log("warn", "External component %s XML parse error: %s", tostring(session.host), tostring(data));
+		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
+
+function stream_callbacks.streamopened(session, attr)
+	-- TODO check id~=nil, from==module.host
+	module:log("debug", "Sending handshake");
+	local handshake = st.stanza("handshake"):text(sha1(attr.id..server_secret, true));
+	session.send(handshake);
+	session.notopen = nil;
+end
+
+function stream_callbacks.streamclosed(session)
+	session.log("debug", "Received </stream:stream>");
+	session:close();
+end
+
+module:hook("stanza/jabber:component:accept:handshake", function(event)
+	session.type = "component";
+	module:log("debug", "Handshake complete");
+	return true; -- READY!
+end);
+
+module:hook("route/remote", function(event)
+	return session and session.send(event.stanza);
+end);
+
+function stream_callbacks.handlestanza(session, stanza)
+	-- Namespaces are icky.
+	if not stanza.attr.xmlns and stanza.name == "handshake" then
+		stanza.attr.xmlns = xmlns_component;
+	end
+	if not stanza.attr.xmlns or stanza.attr.xmlns == "jabber:client" then
+		if not stanza.attr.from then
+			session.log("warn", "Rejecting stanza with no 'from' address");
+			session.send(st.error_reply(stanza, "modify", "bad-request", "Components MUST get a 'from' address on stanzas"));
+			return;
+		end
+		local _, domain = jid_split(stanza.attr.to);
+		if not domain then
+			session.log("warn", "Rejecting stanza with no 'to' address");
+			session.send(st.error_reply(stanza, "modify", "bad-request", "Components MUST get a 'to' address on stanzas"));
+			return;
+		elseif domain ~= session.host then
+			session.log("warn", "Component received stanza with unknown 'to' address");
+			session.send(st.error_reply(stanza, "cancel", "not-allowed", "Component doesn't serve this JID"));
+			return;
+		end
+	end
+	return core_process_stanza(session, stanza);
+end
+
+local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
+local default_stream_attr = { ["xmlns:stream"] = "http://etherx.jabber.org/streams", xmlns = stream_callbacks.default_ns, version = "1.0", id = "" };
+local function session_close(session, reason)
+	if session.destroyed then return; end
+	if session.conn then
+		if session.notopen then
+			session.send("<?xml version='1.0'?>");
+			session.send(st.stanza("stream:stream", default_stream_attr):top_tag());
+		end
+		if reason then
+			if type(reason) == "string" then -- assume stream error
+				module:log("info", "Disconnecting component, <stream:error> is: %s", reason);
+				session.send(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
+					module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(stanza));
+					session.send(stanza);
+				elseif reason.name then -- a stanza
+					module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(reason));
+					session.send(reason);
+				end
+			end
+		end
+		session.send("</stream:stream>");
+		session.conn:close();
+		listener.ondisconnect(session.conn, "stream error");
+	end
+end
+
+function listener.onconnect(conn)
+	session = { type = "component_unauthed", conn = conn, send = function (data) return conn:write(tostring(data)); end, host = module.host };
+
+	-- Logging functions --
+	local conn_name = "jcp"..tostring(session):match("[a-f0-9]+$");
+	session.log = logger.init(conn_name);
+	session.close = session_close;
+	
+	session.log("info", "Outgoing Jabber component connection");
+	
+	local stream = new_xmpp_stream(session, stream_callbacks);
+	session.stream = stream;
+	
+	function session.data(conn, data)
+		local ok, err = stream:feed(data);
+		if ok then return; end
+		module:log("debug", "Received invalid XML (%s) %d bytes: %s", tostring(err), #data, data:sub(1, 300):gsub("[\r\n]+", " "):gsub("[%z\1-\31]", "_"));
+		session:close("not-well-formed");
+	end
+	
+	session.dispatch_stanza = stream_callbacks.handlestanza;
+
+	session.notopen = true;
+	session.send(st.stanza("stream:stream", {
+		to = session.host;
+		["xmlns:stream"] = 'http://etherx.jabber.org/streams';
+		xmlns = xmlns_component;
+	}):top_tag());
+
+	--sessions[conn] = session;
+end
+function listener.onincoming(conn, data)
+	--local session = sessions[conn];
+	session.data(conn, data);
+end
+function listener.ondisconnect(conn, err)
+	--local session = sessions[conn];
+	if session then
+		(session.log or log)("info", "component disconnected: %s (%s)", tostring(session.host), tostring(err));
+		if session.on_destroy then session:on_destroy(err); end
+		--sessions[conn] = nil;
+		for k in pairs(session) do
+			if k ~= "log" and k ~= "close" then
+				session[k] = nil;
+			end
+		end
+		session.destroyed = true;
+		session = nil;
+	end
+	__conn = nil;
+	module:log("error", "connection lost");
+end
+
+function connect()
+	------------------------
+	-- Taken from net.http
+	local conn = socket.tcp ( )
+	conn:settimeout ( 10 )
+	local ok, err = conn:connect ( server_host , server_port )
+	if not ok and err ~= "timeout" then
+		return nil, err;
+	end
+
+	local handler , conn = server.wrapclient ( conn , server_host , server_port , listener , "*l")
+	__conn = conn;
+	------------------------
+	return true;
+end
+assert(connect());
+