cryptpad/NetfluxWebsocketSrv.js

200 lines
6.6 KiB
JavaScript

;(function () { 'use strict';
const Crypto = require('crypto');
const LogStore = require('./storage/LogStore');
const LAG_MAX_BEFORE_DISCONNECT = 30000;
const LAG_MAX_BEFORE_PING = 15000;
const HISTORY_KEEPER_ID = Crypto.randomBytes(8).toString('hex');
const USE_HISTORY_KEEPER = true;
const USE_FILE_BACKUP_STORAGE = true;
let dropUser;
const now = function () { return (new Date()).getTime(); };
const sendMsg = function (ctx, user, msg) {
try {
console.log('<' + JSON.stringify(msg));
user.socket.send(JSON.stringify(msg));
} catch (e) {
console.log(e.stack);
dropUser(ctx, user);
}
};
const sendChannelMessage = function (ctx, channel, msgStruct) {
msgStruct.unshift(0);
channel.forEach(function (user) {
if(msgStruct[2] !== 'MSG' || user.id !== msgStruct[1]) { // We don't want to send back a message to its sender, in order to save bandwidth
sendMsg(ctx, user, msgStruct);
}
});
if (USE_HISTORY_KEEPER && msgStruct[2] === 'MSG') {
ctx.store.message(channel.id, JSON.stringify(msgStruct), function () { });
}
};
dropUser = function (ctx, user) {
if (user.socket.readyState !== 2 /* WebSocket.CLOSING */
&& user.socket.readyState !== 3 /* WebSocket.CLOSED */)
{
try {
user.socket.close();
} catch (e) {
console.log("Failed to disconnect ["+user.id+"], attempting to terminate");
try {
user.socket.terminate();
} catch (ee) {
console.log("Failed to terminate ["+user.id+"] *shrug*");
}
}
}
delete ctx.users[user.id];
Object.keys(ctx.channels).forEach(function (chanName) {
let chan = ctx.channels[chanName];
let idx = chan.indexOf(user);
if (idx < 0) { return; }
console.log("Removing ["+user.id+"] from channel ["+chanName+"]");
chan.splice(idx, 1);
if (chan.length === 0) {
console.log("Removing empty channel ["+chanName+"]");
delete ctx.channels[chanName];
} else {
sendChannelMessage(ctx, chan, [user.id, 'LEAVE', chanName, 'Quit: [ dropUser() ]']);
}
});
};
const getHistory = function (ctx, channelName, handler) {
ctx.store.getMessages(channelName, function (msgStr) { handler(JSON.parse(msgStr)); });
};
const randName = function () { return Crypto.randomBytes(16).toString('hex'); };
const handleMessage = function (ctx, user, msg) {
let json = JSON.parse(msg);
let seq = json.shift();
let cmd = json[0];
let obj = json[1];
user.timeOfLastMessage = now();
user.pingOutstanding = false;
if (cmd === 'JOIN') {
if (obj && obj.length !== 32) {
sendMsg(ctx, user, [seq, 'ERROR', 'ENOENT', obj]);
return;
}
let chanName = obj || randName();
sendMsg(ctx, user, [seq, 'JACK', chanName]);
let chan = ctx.channels[chanName] = ctx.channels[chanName] || [];
chan.id = chanName;
if (USE_HISTORY_KEEPER) {
sendMsg(ctx, user, [0, HISTORY_KEEPER_ID, 'JOIN', chanName]);
}
chan.forEach(function (u) { sendMsg(ctx, user, [0, u.id, 'JOIN', chanName]); });
chan.push(user);
sendChannelMessage(ctx, chan, [user.id, 'JOIN', chanName]);
return;
}
if (cmd === 'MSG') {
if (obj === HISTORY_KEEPER_ID) {
let parsed;
try { parsed = JSON.parse(json[2]); } catch (err) { console.error(err); return; }
if (parsed[0] === 'GET_HISTORY') {
getHistory(ctx, parsed[1], function (msg) {
sendMsg(ctx, user, [0, HISTORY_KEEPER_ID, 'MSG', user.id, JSON.stringify(msg)]);
});
sendMsg(ctx, user, [0, HISTORY_KEEPER_ID, 'MSG', user.id, 0]);
}
return;
}
if (obj && !ctx.channels[obj] && !ctx.users[obj]) {
sendMsg(ctx, user, [seq, 'ERROR', 'ENOENT', obj]);
return;
}
sendMsg(ctx, user, [seq, 'ACK']);
let target;
json.unshift(user.id);
if ((target = ctx.channels[obj])) {
sendChannelMessage(ctx, target, json);
return;
}
if ((target = ctx.users[obj])) {
json.unshift(0);
sendMsg(ctx, target, json);
return;
}
}
if (cmd === 'LEAVE') {
let err;
let chan;
let idx;
if (!obj) { err = 'EINVAL'; obj = 'undefined';}
if (!err && !(chan = ctx.channels[obj])) { err = 'ENOENT'; }
if (!err && (idx = chan.indexOf(user)) === -1) { err = 'NOT_IN_CHAN'; }
if (err) {
sendMsg(ctx, user, [seq, 'ERROR', err, obj]);
return;
}
sendMsg(ctx, user, [seq, 'ACK']);
json.unshift(user.id);
sendChannelMessage(ctx, chan, [user.id, 'LEAVE', chan.id]);
chan.splice(idx, 1);
}
if (cmd === 'PING') {
sendMsg(ctx, user, [seq, 'ACK']);
return;
}
};
let run = module.exports.run = function (storage, socketServer) {
let ctx = {
users: {},
channels: {},
store: (USE_FILE_BACKUP_STORAGE) ? LogStore.create('messages.log', storage) : storage
};
setInterval(function () {
Object.keys(ctx.users).forEach(function (userId) {
let u = ctx.users[userId];
if (now() - u.timeOfLastMessage > LAG_MAX_BEFORE_DISCONNECT) {
dropUser(ctx, u);
} else if (!u.pingOutstanding && now() - u.timeOfLastMessage > LAG_MAX_BEFORE_PING) {
sendMsg(ctx, u, [0, '', 'PING', now()]);
u.pingOutstanding = true;
}
});
}, 5000);
socketServer.on('connection', function(socket) {
if(socket.upgradeReq.url !== '/cryptpad_websocket') { return; }
let conn = socket.upgradeReq.connection;
let user = {
addr: conn.remoteAddress + '|' + conn.remotePort,
socket: socket,
id: randName(),
timeOfLastMessage: now(),
pingOutstanding: false
};
ctx.users[user.id] = user;
sendMsg(ctx, user, [0, '', 'IDENT', user.id]);
socket.on('message', function(message) {
console.log('>'+message);
try {
handleMessage(ctx, user, message);
} catch (e) {
console.log(e.stack);
dropUser(ctx, user);
}
});
socket.on('close', function (evt) {
for (let userId in ctx.users) {
if (ctx.users[userId].socket === socket) {
dropUser(ctx, ctx.users[userId]);
}
}
});
});
};
}());