plugins/mod_websocket.lua
changeset 6397 6f75f8043936
child 6796 2bf1b7e2149a
equal deleted inserted replaced
6396:17b54f523796 6397:6f75f8043936
       
     1 -- Prosody IM
       
     2 -- Copyright (C) 2012-2014 Florian Zeitz
       
     3 --
       
     4 -- This project is MIT/X11 licensed. Please see the
       
     5 -- COPYING file in the source package for more information.
       
     6 --
       
     7 
       
     8 module:set_global();
       
     9 
       
    10 local add_filter = require "util.filters".add_filter;
       
    11 local sha1 = require "util.hashes".sha1;
       
    12 local base64 = require "util.encodings".base64.encode;
       
    13 local st = require "util.stanza";
       
    14 local parse_xml = require "util.xml".parse;
       
    15 local portmanager = require "core.portmanager";
       
    16 local sm_destroy_session = sessionmanager.destroy_session;
       
    17 local log = module._log;
       
    18 
       
    19 local websocket_frames = require"net.websocket.frames";
       
    20 local parse_frame = websocket_frames.parse;
       
    21 local build_frame = websocket_frames.build;
       
    22 local build_close = websocket_frames.build_close;
       
    23 local parse_close = websocket_frames.parse_close;
       
    24 
       
    25 local t_concat = table.concat;
       
    26 
       
    27 local consider_websocket_secure = module:get_option_boolean("consider_websocket_secure");
       
    28 local cross_domain = module:get_option("cross_domain_websocket");
       
    29 if cross_domain then
       
    30 	if cross_domain == true then
       
    31 		cross_domain = "*";
       
    32 	elseif type(cross_domain) == "table" then
       
    33 		cross_domain = t_concat(cross_domain, ", ");
       
    34 	end
       
    35 	if type(cross_domain) ~= "string" then
       
    36 		cross_domain = nil;
       
    37 	end
       
    38 end
       
    39 
       
    40 local xmlns_framing = "urn:ietf:params:xml:ns:xmpp-framing";
       
    41 local xmlns_streams = "http://etherx.jabber.org/streams";
       
    42 local xmlns_client = "jabber:client";
       
    43 local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
       
    44 
       
    45 module:depends("c2s")
       
    46 local sessions = module:shared("c2s/sessions");
       
    47 local c2s_listener = portmanager.get_service("c2s").listener;
       
    48 
       
    49 --- Session methods
       
    50 local function session_open_stream(session)
       
    51 	local attr = {
       
    52 		xmlns = xmlns_framing,
       
    53 		version = "1.0",
       
    54 		id = session.streamid or "",
       
    55 		from = session.host
       
    56 	};
       
    57 	session.send(st.stanza("open", attr));
       
    58 end
       
    59 
       
    60 local function session_close(session, reason)
       
    61 	local log = session.log or log;
       
    62 	if session.conn then
       
    63 		if session.notopen then
       
    64 			session:open_stream();
       
    65 		end
       
    66 		if reason then -- nil == no err, initiated by us, false == initiated by client
       
    67 			local stream_error = st.stanza("stream:error");
       
    68 			if type(reason) == "string" then -- assume stream error
       
    69 				stream_error:tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' });
       
    70 			elseif type(reason) == "table" then
       
    71 				if reason.condition then
       
    72 					stream_error:tag(reason.condition, stream_xmlns_attr):up();
       
    73 					if reason.text then
       
    74 						stream_error:tag("text", stream_xmlns_attr):text(reason.text):up();
       
    75 					end
       
    76 					if reason.extra then
       
    77 						stream_error:add_child(reason.extra);
       
    78 					end
       
    79 				elseif reason.name then -- a stanza
       
    80 					stream_error = reason;
       
    81 				end
       
    82 			end
       
    83 			log("debug", "Disconnecting client, <stream:error> is: %s", tostring(stream_error));
       
    84 			session.send(stream_error);
       
    85 		end
       
    86 
       
    87 		session.send(st.stanza("close", { xmlns = xmlns_framing }));
       
    88 		function session.send() return false; end
       
    89 
       
    90 		local reason = (reason and (reason.name or reason.text or reason.condition)) or reason;
       
    91 		session.log("debug", "c2s stream for %s closed: %s", session.full_jid or ("<"..session.ip..">"), reason or "session closed");
       
    92 
       
    93 		-- Authenticated incoming stream may still be sending us stanzas, so wait for </stream:stream> from remote
       
    94 		local conn = session.conn;
       
    95 		if reason == nil and not session.notopen and session.type == "c2s" then
       
    96 			-- Grace time to process data from authenticated cleanly-closed stream
       
    97 			add_task(stream_close_timeout, function ()
       
    98 				if not session.destroyed then
       
    99 					session.log("warn", "Failed to receive a stream close response, closing connection anyway...");
       
   100 					sm_destroy_session(session, reason);
       
   101 					conn:write(build_close(1000, "Stream closed"));
       
   102 					conn:close();
       
   103 				end
       
   104 			end);
       
   105 		else
       
   106 			sm_destroy_session(session, reason);
       
   107 			conn:write(build_close(1000, "Stream closed"));
       
   108 			conn:close();
       
   109 		end
       
   110 	end
       
   111 end
       
   112 
       
   113 
       
   114 --- Filters
       
   115 local function filter_open_close(data)
       
   116 	if not data:find(xmlns_framing, 1, true) then return data; end
       
   117 
       
   118 	local oc = parse_xml(data);
       
   119 	if not oc then return data; end
       
   120 	if oc.attr.xmlns ~= xmlns_framing then return data; end
       
   121 	if oc.name == "close" then return "</stream:stream>"; end
       
   122 	if oc.name == "open" then
       
   123 		oc.name = "stream:stream";
       
   124 		oc.attr.xmlns = nil;
       
   125 		oc.attr["xmlns:stream"] = xmlns_streams;
       
   126 		return oc:top_tag();
       
   127 	end
       
   128 
       
   129 	return data;
       
   130 end
       
   131 function handle_request(event, path)
       
   132 	local request, response = event.request, event.response;
       
   133 	local conn = response.conn;
       
   134 
       
   135 	if not request.headers.sec_websocket_key then
       
   136 		response.headers.content_type = "text/html";
       
   137 		return [[<!DOCTYPE html><html><head><title>Websocket</title></head><body>
       
   138 			<p>It works! Now point your WebSocket client to this URL to connect to Prosody.</p>
       
   139 			</body></html>]];
       
   140 	end
       
   141 
       
   142 	local wants_xmpp = false;
       
   143 	(request.headers.sec_websocket_protocol or ""):gsub("([^,]*),?", function (proto)
       
   144 		if proto == "xmpp" then wants_xmpp = true; end
       
   145 	end);
       
   146 
       
   147 	if not wants_xmpp then
       
   148 		return 501;
       
   149 	end
       
   150 
       
   151 	local function websocket_close(code, message)
       
   152 		conn:write(build_close(code, message));
       
   153 		conn:close();
       
   154 	end
       
   155 
       
   156 	local dataBuffer;
       
   157 	local function handle_frame(frame)
       
   158 		local opcode = frame.opcode;
       
   159 		local length = frame.length;
       
   160 		module:log("debug", "Websocket received frame: opcode=%0x, %i bytes", frame.opcode, #frame.data);
       
   161 
       
   162 		-- Error cases
       
   163 		if frame.RSV1 or frame.RSV2 or frame.RSV3 then -- Reserved bits non zero
       
   164 			websocket_close(1002, "Reserved bits not zero");
       
   165 			return false;
       
   166 		end
       
   167 
       
   168 		if opcode == 0x8 then -- close frame
       
   169 			if length == 1 then
       
   170 				websocket_close(1002, "Close frame with payload, but too short for status code");
       
   171 				return false;
       
   172 			elseif length >= 2 then
       
   173 				local status_code = parse_close(frame.data)
       
   174 				if status_code < 1000 then
       
   175 					websocket_close(1002, "Closed with invalid status code");
       
   176 					return false;
       
   177 				elseif ((status_code > 1003 and status_code < 1007) or status_code > 1011) and status_code < 3000 then
       
   178 					websocket_close(1002, "Closed with reserved status code");
       
   179 					return false;
       
   180 				end
       
   181 			end
       
   182 		end
       
   183 
       
   184 		if opcode >= 0x8 then
       
   185 			if length > 125 then -- Control frame with too much payload
       
   186 				websocket_close(1002, "Payload too large");
       
   187 				return false;
       
   188 			end
       
   189 
       
   190 			if not frame.FIN then -- Fragmented control frame
       
   191 				websocket_close(1002, "Fragmented control frame");
       
   192 				return false;
       
   193 			end
       
   194 		end
       
   195 
       
   196 		if (opcode > 0x2 and opcode < 0x8) or (opcode > 0xA) then
       
   197 			websocket_close(1002, "Reserved opcode");
       
   198 			return false;
       
   199 		end
       
   200 
       
   201 		if opcode == 0x0 and not dataBuffer then
       
   202 			websocket_close(1002, "Unexpected continuation frame");
       
   203 			return false;
       
   204 		end
       
   205 
       
   206 		if (opcode == 0x1 or opcode == 0x2) and dataBuffer then
       
   207 			websocket_close(1002, "Continuation frame expected");
       
   208 			return false;
       
   209 		end
       
   210 
       
   211 		-- Valid cases
       
   212 		if opcode == 0x0 then -- Continuation frame
       
   213 			dataBuffer[#dataBuffer+1] = frame.data;
       
   214 		elseif opcode == 0x1 then -- Text frame
       
   215 			dataBuffer = {frame.data};
       
   216 		elseif opcode == 0x2 then -- Binary frame
       
   217 			websocket_close(1003, "Only text frames are supported");
       
   218 			return;
       
   219 		elseif opcode == 0x8 then -- Close request
       
   220 			websocket_close(1000, "Goodbye");
       
   221 			return;
       
   222 		elseif opcode == 0x9 then -- Ping frame
       
   223 			frame.opcode = 0xA;
       
   224 			conn:write(build_frame(frame));
       
   225 			return "";
       
   226 		elseif opcode == 0xA then -- Pong frame
       
   227 			module:log("warn", "Received unexpected pong frame: " .. tostring(frame.data));
       
   228 			return "";
       
   229 		else
       
   230 			log("warn", "Received frame with unsupported opcode %i", opcode);
       
   231 			return "";
       
   232 		end
       
   233 
       
   234 		if frame.FIN then
       
   235 			local data = t_concat(dataBuffer, "");
       
   236 			dataBuffer = nil;
       
   237 			return data;
       
   238 		end
       
   239 		return "";
       
   240 	end
       
   241 
       
   242 	conn:setlistener(c2s_listener);
       
   243 	c2s_listener.onconnect(conn);
       
   244 
       
   245 	local session = sessions[conn];
       
   246 
       
   247 	session.secure = consider_websocket_secure or session.secure;
       
   248 
       
   249 	session.open_stream = session_open_stream;
       
   250 	session.close = session_close;
       
   251 
       
   252 	local frameBuffer = "";
       
   253 	add_filter(session, "bytes/in", function(data)
       
   254 		local cache = {};
       
   255 		frameBuffer = frameBuffer .. data;
       
   256 		local frame, length = parse_frame(frameBuffer);
       
   257 
       
   258 		while frame do
       
   259 			frameBuffer = frameBuffer:sub(length + 1);
       
   260 			local result = handle_frame(frame);
       
   261 			if not result then return; end
       
   262 			cache[#cache+1] = filter_open_close(result);
       
   263 			frame, length = parse_frame(frameBuffer);
       
   264 		end
       
   265 		return t_concat(cache, "");
       
   266 	end);
       
   267 
       
   268 	add_filter(session, "stanzas/out", function(stanza)
       
   269 		local attr = stanza.attr;
       
   270 		attr.xmlns = attr.xmlns or xmlns_client;
       
   271 		if stanza.name:find("^stream:") then
       
   272 			attr["xmlns:stream"] = attr["xmlns:stream"] or xmlns_streams;
       
   273 		end
       
   274 		return stanza;
       
   275 	end);
       
   276 
       
   277 	add_filter(session, "bytes/out", function(data)
       
   278 		return build_frame({ FIN = true, opcode = 0x01, data = tostring(data)});
       
   279 	end);
       
   280 
       
   281 	response.status_code = 101;
       
   282 	response.headers.upgrade = "websocket";
       
   283 	response.headers.connection = "Upgrade";
       
   284 	response.headers.sec_webSocket_accept = base64(sha1(request.headers.sec_websocket_key .. "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"));
       
   285 	response.headers.sec_webSocket_protocol = "xmpp";
       
   286 	response.headers.access_control_allow_origin = cross_domain;
       
   287 
       
   288 	return "";
       
   289 end
       
   290 
       
   291 function module.add_host(module)
       
   292 	module:depends("http");
       
   293 	module:provides("http", {
       
   294 		name = "websocket";
       
   295 		default_path = "xmpp-websocket";
       
   296 		route = {
       
   297 			["GET"] = handle_request;
       
   298 			["GET /"] = handle_request;
       
   299 		};
       
   300 	});
       
   301 end