refactor(gateway): completely refactor gateway

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hippoz 2021-09-14 17:02:29 +03:00
parent fe124316a4
commit 3cd7fcb5f9
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2 changed files with 210 additions and 238 deletions

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@ -1,7 +1,5 @@
const websockets = require("ws");
const EventEmitter = require("events");
const uuid = require("uuid");
const werift = require("werift");
const { policies, gatewayPingInterval, gatewayPingCheckInterval, clientFacingPingInterval } = require("../../../config");
const { experiments } = require("../../../experiments");
@ -20,276 +18,249 @@ const wsCloseCodes = {
FLOODING: [4007, "Flooding"],
NO_PING: [4008, "No ping"],
};
const closeConnectionWithCode = (ws, code) => ws.close(code[0], code[1]);
class GatewayRTCConnection {
constructor(ws, server) {
class GatewaySession {
constructor() {
this.authenticated = false;
this.user = null;
this.token = null;
this.sessionId = uuid.v4();
// Specific to websocket sessions
this.isWebsocketConnection = false;
this.ws = null;
this.lastPing = new Date();
this.channels = [];
}
setWebsocketClient(ws) {
this.ws = ws;
this.server = server;
this.connection = new werift.RTCPeerConnection();
this.connection.onnegotiationneeded.subscribe(() => this.renegotiate); // TODO: what
this.isWebsocketConnection = true;
}
async answer(offer) {
await this.connection.setRemoteDescription(offer);
await this.connection.setLocalDescription(await this.connection.createAnswer());
return this.connection.localDescription;
async authenticateWithToken(token) {
let user = null;
try {
user = await checkToken(token);
if (!user) return false;
this.token = token;
this.user = user;
this.authenticated = true;
return true;
} catch(e) {
return false;
}
}
async addTrack(track) {
if (!track) return;
this.ws.send(this.server.packet("EVENT_TRACK_NOTIFICATION", {
kind: track.kind
}));
this.connection.addTransceiver(track);
send(name, data) {
this.ws.send(packet(name, data));
}
async renegotiate() {
this.ws.send(this.server.packet("EVENT_RENEGOTIATE_REQUIRED", {}));
isReady() {
return this.authenticated && this.ws;
}
}
class GatewayServer extends EventEmitter {
constructor({ server }) {
super();
this.wss = new websockets.Server({ server: server, path: "/gateway" });
class GatewayHandler {
constructor() {
this.sessionCounters = {};
}
// server event handlers
handleServerConfigRequest() {
return {
path: "/gateway"
};
}
handleServerReady(wss) {
this.wss = wss;
this.pingCheckIntervalFunction = setInterval(() => {
this.wss.clients.forEach((client) => {
if ((new Date() - client.session.lastPing) >= gatewayPingInterval) {
closeConnectionWithCode(client, wsCloseCodes.NO_PING);
client.close(wsCloseCodes.NO_PING[0], wsCloseCodes.NO_PING[1]);
}
});
}, gatewayPingCheckInterval);
}
this.wss.on("close", () => {
clearInterval(this.pingCheckIntervalFunction);
console.log("gateway: websocket server closed");
});
handleServerClose() {
clearInterval(this.pingCheckIntervalFunction);
}
this.wss.on("connection", (ws) => {
if (!policies.allowGatewayConnection) return closeConnectionWithCode(ws, wsCloseCodes.SERVER_DENIED_CONNECTION);
ws.send(packet("HELLO", { pingInterval: clientFacingPingInterval }));
ws.session = {
authenticated: false,
user: null,
sessionId: uuid.v4(),
lastPing: new Date(),
token: null
};
handleConnection(ws) {
const session = new GatewaySession();
session.setWebsocketClient(ws);
session.send("HELLO", { pingInterval: clientFacingPingInterval });
return session;
}
ws.on("close", async () => {
if (ws.session.user && ws.channels) {
if (this.sessionCounters[ws.session.user._id] <= 1) {
this.inChannel(ws.channels[0], (client) => {
console.log(client.session);
client.send(packet("EVENT_CHANNEL_MEMBERS", {
[ws.session.user._id]: {
_id: ws.session.user._id,
username: ws.session.user.username,
status: 0,
status_text: ""
}
}));
handleConnectionClose(ws) {
if (ws.session && ws.session.user && ws.session.channels) {
if (this.sessionCounters[ws.session.user._id] <= 1) {
this.eachInChannel(ws.session.channels[0], (client) => {
if (client.session && client.session.isReady()) {
client.session.send("EVENT_CHANNEL_MEMBERS", {
[ws.session.user._id]: {
_id: ws.session.user._id,
username: ws.session.user.username,
status: 0,
status_text: ""
}
});
}
this.sessionCounters[ws.session.user._id]--;
}
});
}
this.sessionCounters[ws.session.user._id]--;
if (this.sessionCounters[ws.session.user._id] <= 0) {
this.sessionCounters[ws.session.user._id] = null;
delete this.sessionCounters[ws.session.user._id];
}
}
}
if (ws.rtc && ws.rtc.connection) await ws.rtc.connection.close();
handleMessage(senderSession, packet) {
return this[`handle_${packet.opcodeType}`](packet, senderSession);
}
// utility functions
addSessionCounter(id) {
if (!this.sessionCounters[id]) this.sessionCounters[id] = 0;
this.sessionCounters[id]++;
if (this.sessionCounters[id] > policies.perUserMaxGatewayConnections) return false;
return true;
}
getClients() {
return this.wss.clients;
}
eachInChannel(channelId, callback) {
const clients = this.getClients();
clients.forEach((client) => {
if (client.session && client.session.isReady() && client.session.channels.includes(channelId))
callback(client);
});
}
// Gateway message handlers
async handle_YOO({ data }, session) {
if (session.authenticated) return {error: wsCloseCodes.PAYLOAD_ERROR};
try {
if (!(await session.authenticateWithToken(data.token))) return {error: wsCloseCodes.AUTHENTICATION_ERROR};
} catch(e) {
return {error: wsCloseCodes.AUTHENTICATION_ERROR};
}
if (!this.addSessionCounter(session.user._id)) return {error: wsCloseCodes.TOO_MANY_SESSIONS};
const channels = (await Channel.find().lean().sort({ _id: -1 }).limit(50).select("-posts -__v").populate("creator", User.getPulicFields(true))) || [];
session.channels = channels.map(x => x._id.toString());
session.send("YOO_ACK", { session_id: session.sessionId, channels, user: { username: session.user.username, _id: session.user._id }, __global_experiments: experiments });
const channel = session.channels[0];
if (channel) {
const presence = {};
this.eachInChannel(channel, ({ session: remoteSession }) => {
presence[remoteSession.user._id] = {
_id: remoteSession.user._id,
username: remoteSession.user.username,
status: 1,
status_text: "Online"
};
if (remoteSession.sessionId !== session.sessionId) {
remoteSession.send("EVENT_CHANNEL_MEMBERS", {
[session.user._id]: {
_id: session.user._id,
username: session.user.username,
status: 1,
status_text: "Online"
}
});
}
});
ws.on("message", async (data, isBinary) => {
try {
if (isBinary) return closeConnectionWithCode(ws, wsCloseCodes.PAYLOAD_ERROR);
const message = parseMessage(data.toString());
switch (message.opcodeType) {
case "YOO": {
if (ws.session.authenticated) return closeConnectionWithCode(ws, wsCloseCodes.PAYLOAD_ERROR);
// The client has responded to our HELLO with a YOO packet
try {
const user = await checkToken(message.data.token);
if (!user) return closeConnectionWithCode(ws, wsCloseCodes.AUTHENTICATION_ERROR);
ws.session.user = user;
ws.session.authenticated = true;
ws.session.token = message.data.token;
if (!this.sessionCounters[user._id]) this.sessionCounters[user._id] = 0;
this.sessionCounters[user._id]++;
if (this.sessionCounters[user._id] > policies.perUserMaxGatewayConnections) return closeConnectionWithCode(ws, wsCloseCodes.TOO_MANY_SESSIONS);
session.send("EVENT_CHANNEL_MEMBERS", presence);
}
}
// The user is now successfully authenticated, send the YOO_ACK packet
// TODO: This is probably not efficient
async handle_ACTION_PING({ data }, session) {
if (!session.isReady()) return {error: wsCloseCodes.NOT_AUTHENTICATED};
if (data !== "1") throw new Error("msg: ACTION_PING payload data should be a `1`");
let channels = await Channel.find().lean().sort({ _id: -1 }).limit(50).select("-posts -__v").populate("creator", User.getPulicFields(true));
if (!channels) channels = [];
channels = channels.map(x => ({ ...x, _id: x._id.toString() }));
const user = await checkToken(session.token);
if (!user) return {error: wsCloseCodes.AUTHENTICATION_ERROR};
session.lastPing = new Date();
}
ws.channels = channels.map(x => x._id);
async handle_ACTION_CREATE_MESSAGE({ data }, session) {
if (!session.isReady()) return {error: wsCloseCodes.NOT_AUTHENTICATED};
if (typeof data.content !== "string" || typeof data.channel !== "object" || typeof data.channel._id !== "string") throw new Error("msg: invalid fields in json payload");
const messageContent = data.content.trim();
if (messageContent.length > 2000 || messageContent === "") return;
if (data.channel._id.length !== 24) throw new Error("msg: payload has invalid id"); // MONGODB ONLY!!
ws.send(packet("YOO_ACK", { session_id: ws.session.sessionId, channels, user: { username: user.username, _id: user._id }, __global_experiments: experiments }));
let presence = {};
const channel = channels[0];
// Check if the user is in that channel before broadcasting the message
if (!session.channels.includes(data.channel._id)) return {error: wsCloseCodes.NOT_AUTHORIZED};
if (channel) {
this.inChannel(channel._id, (client) => {
presence[client.session.user._id] = {
_id: client.session.user._id,
username: client.session.user.username,
status: 1,
status_text: "Online"
};
if (client.session.sessionId !== ws.session.sessionId) client.send(packet("EVENT_CHANNEL_MEMBERS", {
[ws.session.user._id]: {
_id: ws.session.user._id,
username: ws.session.user.username,
status: 1,
status_text: "Online"
}
}));
});
ws.send(packet("EVENT_CHANNEL_MEMBERS", presence));
}
console.log(`gateway: user ${user.username}: handshake complete`);
} catch (e) {
console.log("gateway:", e);
return closeConnectionWithCode(ws, wsCloseCodes.AUTHENTICATION_ERROR);
}
break;
}
case "ACTION_PING": {
if (!this.authMessage(ws)) return;
if (message.data !== "1") throw new Error("msg: ACTION_PING payload data should be a `1`");
const user = await checkToken(ws.session.token);
if (!user) return closeConnectionWithCode(ws, wsCloseCodes.AUTHENTICATION_ERROR);
ws.session.lastPing = new Date();
break;
}
case "ACTION_CREATE_MESSAGE": {
if (!this.authMessage(ws)) return;
if (typeof message.data.content !== "string" || typeof message.data.channel !== "object" || typeof message.data.channel._id !== "string") throw new Error("msg: invalid fields in json payload");
const messageContent = message.data.content.trim();
if (messageContent.length > 2000) return;
if (messageContent === "") return;
if (message.data.channel._id.length !== 24) throw new Error("msg: payload has invalid id"); // MONGODB ONLY!!
// Check if the user is in that channel before broadcasting the message
if (!ws.channels.includes(message.data.channel._id)) return closeConnectionWithCode(ws, wsCloseCodes.NOT_AUTHORIZED);
this.broadcast(message.data.channel._id, packet("EVENT_CREATE_MESSAGE", {
content: messageContent,
channel: {
_id: message.data.channel._id
},
author: {
_id: ws.session.user._id,
username: ws.session.user.username
},
_id: uuid.v4()
}));
break;
}
case "ACTION_VOICE_REQUEST_SESSION": {
if (!experiments.voiceSFUTesting) return;
// just send ourselves as the voice server lol
ws.send(packet("EVENT_VOICE_ASSIGN_SERVER", {
reportTo: "/gateway",
channel: message.data.channel
}));
break;
}
case "ACTION_VOICE_CONNECTION_REQUEST": {
if (!this.authMessage(ws)) return;
if (!experiments.voiceSFUTesting) return;
const offer = message.data.offer;
const channel = message.data.channel;
if (!channel || !channel._id) throw new Error("Client did not send a valid channel in ACTION_VOICE_CONNECTION_REQUEST");
if (!offer) throw new Error("Client did not send any offer in ACTION_VOICE_CONNECTION_REQUEST");
let isNewConnection = true;
if (ws.rtc) {
isNewConnection = false;
} else {
ws.rtc = new GatewayRTCConnection(ws, this);
}
if (isNewConnection) {
ws.rtc.connection.onTransceiver.subscribe(async (transceiver) => {
const [track] = await transceiver.onTrack.asPromise();
this.inChannel(channel._id, (otherWs) => {
if (!this.clientRTCReady(otherWs)) return;
if (otherWs.session.sessionId === ws.session.sessionId) return; // Don't perform the actions below on ourselves
otherWs.rtc.addTrack(track);
otherWs.rtc.renegotiate();
});
});
}
ws.send(packet("EVENT_VOICE_CONNECTION_ANSWER", {
answer: await ws.rtc.answer(offer)
}));
if (isNewConnection) {
this.inChannel(channel._id, (otherWs) => {
if (!this.clientRTCReady(otherWs)) return;
if (otherWs.session.sessionId === ws.session.sessionId) return; // Don't perform the actions below on ourselves
const otherReceivers = otherWs.rtc.connection.getReceivers();
for (let i = 0; i < otherReceivers.length; i++) {
const otherRecevier = otherReceivers[i];
ws.rtc.addTrack(otherRecevier.tracks[0]);
}
});
ws.rtc.renegotiate();
}
break;
}
}
} catch(e) {
console.error("gateway:", e);
return closeConnectionWithCode(ws, wsCloseCodes.PAYLOAD_ERROR);
}
this.eachInChannel(data.channel._id, ({ session: remoteSession }) => {
remoteSession.send("EVENT_CREATE_MESSAGE", {
content: messageContent,
channel: {
_id: data.channel._id
},
author: {
_id: session.user._id,
username: session.user.username
},
_id: uuid.v4()
});
});
}
}
GatewayServer.prototype.broadcast = function(channelId, data) {
this.wss.clients.forEach((client) => {
if (this.clientReady(client) && client.channels.includes(channelId)) client.send(data);
});
};
GatewayServer.prototype.inChannel = function(channelId, func) {
this.wss.clients.forEach((client) => {
if (this.clientReady(client) && client.channels.includes(channelId)) func(client);
});
};
GatewayServer.prototype.clientReady = function(ws) {
return ws.readyState === websockets.OPEN && ws.session && ws.session.authenticated;
};
GatewayServer.prototype.clientRTCReady = function(ws) {
return ws.rtc; // TODO: add more checks
};
GatewayServer.prototype.authMessage = function(ws) {
if (!this.clientReady(ws)) {
closeConnectionWithCode(ws, wsCloseCodes.NOT_AUTHENTICATED);
return false;
class GatewayServer {
constructor(httpServer) {
this.httpServer = httpServer;
this.wss = null;
this.handler = null;
}
return true;
};
module.exports = GatewayServer;
bindHandler(handler) {
if (this.wss) throw new Error("GatewayServer: cannot bindHandler() to a server which already has a bound handler.");
const newHandler = new handler();
this.handler = newHandler;
this.wss = new websockets.Server({ server: this.httpServer, ...(this.handler.handleServerConfigRequest()) });
this.handler.handleServerReady(this.wss);
this.wss.on("close", () => this.handler.handleServerClose());
this.wss.on("connection", (ws) => {
const session = this.handler.handleConnection(ws);
if (!session)
return ws.close();
if (session.__error)
return ws.close(session.__error[0], session.__error[1]);
ws.session = session;
ws.on("message", async (data, isBinary) => {
try {
if (isBinary || !ws.session) return ws.close(wsCloseCodes.PAYLOAD_ERROR[0], wsCloseCodes.PAYLOAD_ERROR[1]);
const status = await this.handler.handleMessage(ws.session, parseMessage(data.toString()));
if (status && status.error) {
return ws.close(status.error[0], status.error[1]);
}
} catch(e) {
console.error("GatewayServer: unexpected error while attempting to handle payload", e);
ws.close(wsCloseCodes.PAYLOAD_ERROR[0], wsCloseCodes.PAYLOAD_ERROR[1]);
}
});
ws.on("close", (code, reason) => {
this.handler.handleConnectionClose(ws, code, reason);
});
});
}
}
module.exports = { GatewayServer, GatewayHandler };

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@ -1,6 +1,6 @@
const config = require("./config");
const apiRoute = require("./api/v1");
const GatewayServerV2 = require("./api/v2/gateway/index");
const { GatewayServer, GatewayHandler } = require("./api/v2/gateway/index");
const express = require("express");
const cookieParser = require("cookie-parser");
@ -10,7 +10,8 @@ const http = require("http");
const app = express();
const httpServer = http.createServer(app);
new GatewayServerV2({ server: httpServer });
const gatewayServer = new GatewayServer(httpServer);
gatewayServer.bindHandler(GatewayHandler);
app.use(express.urlencoded({ extended: false }));
app.use(express.json());