-- 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. -- -- luacheck: ignore 431/log module:set_global(); local add_task = require "util.timer".add_task; 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 contains_token = require "util.http".contains_token; local portmanager = require "core.portmanager"; local sm_destroy_session = require"core.sessionmanager".destroy_session; local log = module._log; local dbuffer = require "util.dbuffer"; 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 stanza_size_limit = module:get_option_number("c2s_stanza_size_limit", 1024 * 256); local frame_buffer_limit = module:get_option_number("websocket_frame_buffer_limit", 2 * stanza_size_limit); local frame_fragment_limit = module:get_option_number("websocket_frame_fragment_limit", 8); local stream_close_timeout = module:get_option_number("c2s_close_timeout", 5); local consider_websocket_secure = module:get_option_boolean("consider_websocket_secure"); local cross_domain = module:get_option("cross_domain_websocket"); if cross_domain ~= nil then module:log("info", "The 'cross_domain_websocket' option has been deprecated"); 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, from, to) local attr = { xmlns = xmlns_framing, ["xml:lang"] = "en", version = "1.0", id = session.streamid or "", from = from or session.host, to = to, }; if session.stream_attrs then session:stream_attrs(from, to, attr) end 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, is: %s", stream_error); session.send(stream_error); end session.send(st.stanza("close", { xmlns = xmlns_framing })); function session.send() return false; end -- luacheck: ignore 422/reason -- FIXME reason should be handled in common place 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 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 ""; 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 local default_get_response_text = "It works! Now point your WebSocket client to this URL to connect to Prosody." local websocket_get_response_text = module:get_option_string("websocket_get_response_text", default_get_response_text) local default_get_response_body = [[Websocket

]]..websocket_get_response_text..[[

]] local websocket_get_response_body = module:get_option_string("websocket_get_response_body", default_get_response_body) local function validate_frame(frame, max_length) local opcode, length = frame.opcode, frame.length; if max_length and length > max_length then return false, 1009, "Payload too large"; end -- Error cases if frame.RSV1 or frame.RSV2 or frame.RSV3 then -- Reserved bits non zero return false, 1002, "Reserved bits not zero"; end if opcode == 0x8 and frame.data then -- close frame if length == 1 then return false, 1002, "Close frame with payload, but too short for status code"; elseif length >= 2 then local status_code = parse_close(frame.data) if status_code < 1000 then return false, 1002, "Closed with invalid status code"; elseif ((status_code > 1003 and status_code < 1007) or status_code > 1011) and status_code < 3000 then return false, 1002, "Closed with reserved status code"; end end end if opcode >= 0x8 then if length > 125 then -- Control frame with too much payload return false, 1002, "Payload too large"; end if not frame.FIN then -- Fragmented control frame return false, 1002, "Fragmented control frame"; end end if (opcode > 0x2 and opcode < 0x8) or (opcode > 0xA) then return false, 1002, "Reserved opcode"; end -- Check opcode if opcode == 0x2 then -- Binary frame return false, 1003, "Only text frames are supported, RFC 7395 3.2"; elseif opcode == 0x8 then -- Close request return false, 1000, "Goodbye"; end -- Other (XMPP-specific) validity checks if not frame.FIN then return false, 1003, "Continuation frames are not supported, RFC 7395 3.3.3"; end if opcode == 0x01 and frame.data and frame.data:byte(1, 1) ~= 60 then return false, 1007, "Invalid payload start character, RFC 7395 3.3.3"; end return true; end function handle_request(event) local request, response = event.request, event.response; local conn = response.conn; conn.starttls = false; -- Prevent mod_tls from believing starttls can be done if not request.headers.sec_websocket_key or request.method ~= "GET" then return module:fire_event("http-message", { response = event.response; --- title = "Prosody WebSocket endpoint"; message = websocket_get_response_text; warning = not (consider_websocket_secure or request.secure) and "This endpoint is not considered secure!" or nil; }) or websocket_get_response_body; end local wants_xmpp = contains_token(request.headers.sec_websocket_protocol or "", "xmpp"); if not wants_xmpp then module:log("debug", "Client didn't want to talk XMPP, list of protocols was %s", request.headers.sec_websocket_protocol or "(empty)"); return 501; end local function websocket_close(code, message) conn:write(build_close(code, message)); conn:close(); end local function websocket_handle_error(session, code, message) if code == 1009 then -- stanza size limit exceeded -- we close the session, rather than the connection, -- otherwise a resuming client will simply resend the -- offending stanza session:close({ condition = "policy-violation", text = "stanza too large" }); else websocket_close(code, message); end end local function handle_frame(frame) module:log("debug", "Websocket received frame: opcode=%0x, %i bytes", frame.opcode, #frame.data); -- Check frame makes sense local frame_ok, err_status, err_text = validate_frame(frame, stanza_size_limit); if not frame_ok then return frame_ok, err_status, err_text; end local opcode = frame.opcode; if opcode == 0x9 then -- Ping frame frame.opcode = 0xA; frame.MASK = false; -- Clients send masked frames, servers don't, see #1484 conn:write(build_frame(frame)); return ""; elseif opcode == 0xA then -- Pong frame, MAY be sent unsolicited, eg as keepalive return ""; elseif opcode ~= 0x1 then -- Not text frame (which is all we support) log("warn", "Received frame with unsupported opcode %i", opcode); return ""; end return frame.data; end conn:setlistener(c2s_listener); c2s_listener.onconnect(conn); local session = sessions[conn]; -- Use upstream IP if a HTTP proxy was used -- See mod_http and #540 session.ip = request.ip; session.secure = consider_websocket_secure or request.secure or session.secure; session.websocket_request = request; session.open_stream = session_open_stream; session.close = session_close; local frameBuffer = dbuffer.new(frame_buffer_limit, frame_fragment_limit); add_filter(session, "bytes/in", function(data) if not frameBuffer:write(data) then session.log("warn", "websocket frame buffer full - terminating session"); session:close({ condition = "resource-constraint", text = "frame buffer exceeded" }); return; end local cache = {}; local frame, length, partial = parse_frame(frameBuffer); while frame do frameBuffer:discard(length); local result, err_status, err_text = handle_frame(frame); if not result then websocket_handle_error(session, err_status, err_text); break; end cache[#cache+1] = filter_open_close(result); frame, length, partial = parse_frame(frameBuffer); end if partial then -- The header of the next frame is already in the buffer, run -- some early validation here local frame_ok, err_status, err_text = validate_frame(partial, stanza_size_limit); if not frame_ok then websocket_handle_error(session, err_status, err_text); end end return t_concat(cache, ""); end); add_filter(session, "stanzas/out", function(stanza) stanza = st.clone(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, -1000); 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"; module:fire_event("websocket-session", { session = session, request = request }); session.log("debug", "Sending WebSocket handshake"); return ""; end local function keepalive(event) local session = event.session; if session.open_stream == session_open_stream then return session.conn:write(build_frame({ opcode = 0x9, FIN = true })); end end module:hook("c2s-read-timeout", keepalive, -0.9); module:depends("http"); module:provides("http", { name = "websocket"; default_path = "xmpp-websocket"; route = { ["GET"] = handle_request; ["GET /"] = handle_request; }; }); function module.add_host(module) module:hook("c2s-read-timeout", keepalive, -0.9); end