Diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/mod_websocket.lua	Fri Sep 05 03:47:39 2014 +0200
@@ -0,0 +1,301 @@
+-- Prosody IM
+-- Copyright (C) 2012-2014 Florian Zeitz
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+module:set_global();
+
+local add_filter = require "util.filters".add_filter;
+local sha1 = require "util.hashes".sha1;
+local base64 = require "util.encodings".base64.encode;
+local st = require "util.stanza";
+local parse_xml = require "util.xml".parse;
+local portmanager = require "core.portmanager";
+local sm_destroy_session = sessionmanager.destroy_session;
+local log = module._log;
+
+local websocket_frames = require"net.websocket.frames";
+local parse_frame = websocket_frames.parse;
+local build_frame = websocket_frames.build;
+local build_close = websocket_frames.build_close;
+local parse_close = websocket_frames.parse_close;
+
+local t_concat = table.concat;
+
+local consider_websocket_secure = module:get_option_boolean("consider_websocket_secure");
+local cross_domain = module:get_option("cross_domain_websocket");
+if cross_domain then
+	if cross_domain == true then
+		cross_domain = "*";
+	elseif type(cross_domain) == "table" then
+		cross_domain = t_concat(cross_domain, ", ");
+	end
+	if type(cross_domain) ~= "string" then
+		cross_domain = nil;
+	end
+end
+
+local xmlns_framing = "urn:ietf:params:xml:ns:xmpp-framing";
+local xmlns_streams = "http://etherx.jabber.org/streams";
+local xmlns_client = "jabber:client";
+local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
+
+module:depends("c2s")
+local sessions = module:shared("c2s/sessions");
+local c2s_listener = portmanager.get_service("c2s").listener;
+
+--- Session methods
+local function session_open_stream(session)
+	local attr = {
+		xmlns = xmlns_framing,
+		version = "1.0",
+		id = session.streamid or "",
+		from = session.host
+	};
+	session.send(st.stanza("open", attr));
+end
+
+local function session_close(session, reason)
+	local log = session.log or log;
+	if session.conn then
+		if session.notopen then
+			session:open_stream();
+		end
+		if reason then -- nil == no err, initiated by us, false == initiated by client
+			local stream_error = st.stanza("stream:error");
+			if type(reason) == "string" then -- assume stream error
+				stream_error:tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' });
+			elseif type(reason) == "table" then
+				if reason.condition then
+					stream_error:tag(reason.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
+				elseif reason.name then -- a stanza
+					stream_error = reason;
+				end
+			end
+			log("debug", "Disconnecting client, <stream:error> is: %s", tostring(stream_error));
+			session.send(stream_error);
+		end
+
+		session.send(st.stanza("close", { xmlns = xmlns_framing }));
+		function session.send() return false; end
+
+		local reason = (reason and (reason.name or reason.text or reason.condition)) or reason;
+		session.log("debug", "c2s stream for %s closed: %s", session.full_jid or ("<"..session.ip..">"), reason or "session closed");
+
+		-- Authenticated incoming stream may still be sending us stanzas, so wait for </stream:stream> from remote
+		local conn = session.conn;
+		if reason == nil and not session.notopen and session.type == "c2s" then
+			-- Grace time to process data from authenticated cleanly-closed stream
+			add_task(stream_close_timeout, function ()
+				if not session.destroyed then
+					session.log("warn", "Failed to receive a stream close response, closing connection anyway...");
+					sm_destroy_session(session, reason);
+					conn:write(build_close(1000, "Stream closed"));
+					conn:close();
+				end
+			end);
+		else
+			sm_destroy_session(session, reason);
+			conn:write(build_close(1000, "Stream closed"));
+			conn:close();
+		end
+	end
+end
+
+
+--- Filters
+local function filter_open_close(data)
+	if not data:find(xmlns_framing, 1, true) then return data; end
+
+	local oc = parse_xml(data);
+	if not oc then return data; end
+	if oc.attr.xmlns ~= xmlns_framing then return data; end
+	if oc.name == "close" then return "</stream:stream>"; end
+	if oc.name == "open" then
+		oc.name = "stream:stream";
+		oc.attr.xmlns = nil;
+		oc.attr["xmlns:stream"] = xmlns_streams;
+		return oc:top_tag();
+	end
+
+	return data;
+end
+function handle_request(event, path)
+	local request, response = event.request, event.response;
+	local conn = response.conn;
+
+	if not request.headers.sec_websocket_key then
+		response.headers.content_type = "text/html";
+		return [[<!DOCTYPE html><html><head><title>Websocket</title></head><body>
+			<p>It works! Now point your WebSocket client to this URL to connect to Prosody.</p>
+			</body></html>]];
+	end
+
+	local wants_xmpp = false;
+	(request.headers.sec_websocket_protocol or ""):gsub("([^,]*),?", function (proto)
+		if proto == "xmpp" then wants_xmpp = true; end
+	end);
+
+	if not wants_xmpp then
+		return 501;
+	end
+
+	local function websocket_close(code, message)
+		conn:write(build_close(code, message));
+		conn:close();
+	end
+
+	local dataBuffer;
+	local function handle_frame(frame)
+		local opcode = frame.opcode;
+		local length = frame.length;
+		module:log("debug", "Websocket received frame: opcode=%0x, %i bytes", frame.opcode, #frame.data);
+
+		-- Error cases
+		if frame.RSV1 or frame.RSV2 or frame.RSV3 then -- Reserved bits non zero
+			websocket_close(1002, "Reserved bits not zero");
+			return false;
+		end
+
+		if opcode == 0x8 then -- close frame
+			if length == 1 then
+				websocket_close(1002, "Close frame with payload, but too short for status code");
+				return false;
+			elseif length >= 2 then
+				local status_code = parse_close(frame.data)
+				if status_code < 1000 then
+					websocket_close(1002, "Closed with invalid status code");
+					return false;
+				elseif ((status_code > 1003 and status_code < 1007) or status_code > 1011) and status_code < 3000 then
+					websocket_close(1002, "Closed with reserved status code");
+					return false;
+				end
+			end
+		end
+
+		if opcode >= 0x8 then
+			if length > 125 then -- Control frame with too much payload
+				websocket_close(1002, "Payload too large");
+				return false;
+			end
+
+			if not frame.FIN then -- Fragmented control frame
+				websocket_close(1002, "Fragmented control frame");
+				return false;
+			end
+		end
+
+		if (opcode > 0x2 and opcode < 0x8) or (opcode > 0xA) then
+			websocket_close(1002, "Reserved opcode");
+			return false;
+		end
+
+		if opcode == 0x0 and not dataBuffer then
+			websocket_close(1002, "Unexpected continuation frame");
+			return false;
+		end
+
+		if (opcode == 0x1 or opcode == 0x2) and dataBuffer then
+			websocket_close(1002, "Continuation frame expected");
+			return false;
+		end
+
+		-- Valid cases
+		if opcode == 0x0 then -- Continuation frame
+			dataBuffer[#dataBuffer+1] = frame.data;
+		elseif opcode == 0x1 then -- Text frame
+			dataBuffer = {frame.data};
+		elseif opcode == 0x2 then -- Binary frame
+			websocket_close(1003, "Only text frames are supported");
+			return;
+		elseif opcode == 0x8 then -- Close request
+			websocket_close(1000, "Goodbye");
+			return;
+		elseif opcode == 0x9 then -- Ping frame
+			frame.opcode = 0xA;
+			conn:write(build_frame(frame));
+			return "";
+		elseif opcode == 0xA then -- Pong frame
+			module:log("warn", "Received unexpected pong frame: " .. tostring(frame.data));
+			return "";
+		else
+			log("warn", "Received frame with unsupported opcode %i", opcode);
+			return "";
+		end
+
+		if frame.FIN then
+			local data = t_concat(dataBuffer, "");
+			dataBuffer = nil;
+			return data;
+		end
+		return "";
+	end
+
+	conn:setlistener(c2s_listener);
+	c2s_listener.onconnect(conn);
+
+	local session = sessions[conn];
+
+	session.secure = consider_websocket_secure or session.secure;
+
+	session.open_stream = session_open_stream;
+	session.close = session_close;
+
+	local frameBuffer = "";
+	add_filter(session, "bytes/in", function(data)
+		local cache = {};
+		frameBuffer = frameBuffer .. data;
+		local frame, length = parse_frame(frameBuffer);
+
+		while frame do
+			frameBuffer = frameBuffer:sub(length + 1);
+			local result = handle_frame(frame);
+			if not result then return; end
+			cache[#cache+1] = filter_open_close(result);
+			frame, length = parse_frame(frameBuffer);
+		end
+		return t_concat(cache, "");
+	end);
+
+	add_filter(session, "stanzas/out", function(stanza)
+		local attr = stanza.attr;
+		attr.xmlns = attr.xmlns or xmlns_client;
+		if stanza.name:find("^stream:") then
+			attr["xmlns:stream"] = attr["xmlns:stream"] or xmlns_streams;
+		end
+		return stanza;
+	end);
+
+	add_filter(session, "bytes/out", function(data)
+		return build_frame({ FIN = true, opcode = 0x01, data = tostring(data)});
+	end);
+
+	response.status_code = 101;
+	response.headers.upgrade = "websocket";
+	response.headers.connection = "Upgrade";
+	response.headers.sec_webSocket_accept = base64(sha1(request.headers.sec_websocket_key .. "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"));
+	response.headers.sec_webSocket_protocol = "xmpp";
+	response.headers.access_control_allow_origin = cross_domain;
+
+	return "";
+end
+
+function module.add_host(module)
+	module:depends("http");
+	module:provides("http", {
+		name = "websocket";
+		default_path = "xmpp-websocket";
+		route = {
+			["GET"] = handle_request;
+			["GET /"] = handle_request;
+		};
+	});
+end