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-rw-r--r--plugins/mod_websocket.lua341
1 files changed, 341 insertions, 0 deletions
diff --git a/plugins/mod_websocket.lua b/plugins/mod_websocket.lua
new file mode 100644
index 00000000..3c96f780
--- /dev/null
+++ b/plugins/mod_websocket.lua
@@ -0,0 +1,341 @@
+-- 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 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 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_set("cross_domain_websocket", {});
+if cross_domain:contains("*") or cross_domain:contains(true) then
+ cross_domain = true;
+end
+
+local function check_origin(origin)
+ if cross_domain == true then
+ return true;
+ end
+ return cross_domain:contains(origin);
+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, <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)
+ 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 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 = 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
+
+ if not check_origin(request.headers.origin or "") then
+ module:log("debug", "Origin %s is not allowed by 'cross_domain_websocket'", request.headers.origin or "(missing header)");
+ return 403;
+ 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, MAY be sent unsolicited, eg as keepalive
+ 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, -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";
+
+ 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);
+
+function module.add_host(module)
+ module:depends("http");
+ module:provides("http", {
+ name = "websocket";
+ default_path = "xmpp-websocket";
+ route = {
+ ["GET"] = handle_request;
+ ["GET /"] = handle_request;
+ };
+ });
+ module:hook("c2s-read-timeout", keepalive, -0.9);
+
+ if cross_domain ~= true then
+ local url = require "socket.url";
+ local ws_url = module:http_url("websocket", "xmpp-websocket");
+ local url_components = url.parse(ws_url);
+ -- The 'Origin' consists of the base URL without path
+ url_components.path = nil;
+ local this_origin = url.build(url_components);
+ local local_cross_domain = module:get_option_set("cross_domain_websocket", { this_origin });
+ -- Don't add / remove something added by another host
+ -- This might be weird with random load order
+ local_cross_domain:exclude(cross_domain);
+ cross_domain:include(local_cross_domain);
+ function module.unload()
+ cross_domain:exclude(local_cross_domain);
+ end
+ end
+end