enigma-bbs/core/servers/chat/mrc_multiplexer.js

320 lines
11 KiB
JavaScript

/* jslint node: true */
'use strict';
// ENiGMA½
const Log = require('../../logger.js').log;
const { ServerModule } = require('../../server_module.js');
const Config = require('../../config.js').get;
const { Errors } = require('../../enig_error.js');
const SysProps = require('../../system_property.js');
const StatLog = require('../../stat_log.js');
// deps
const net = require('net');
const _ = require('lodash');
const os = require('os');
// MRC
const protocolVersion = '1.2.9';
const lineDelimiter = new RegExp('\r\n|\r|\n');
const ModuleInfo = exports.moduleInfo = {
name : 'MRC',
desc : 'An MRC Chat Multiplexer',
author : 'RiPuk',
packageName : 'codes.l33t.enigma.mrc.server',
notes : 'https://bbswiki.bottomlessabyss.net/index.php?title=MRC_Chat_platform',
};
const connectedSockets = new Set();
exports.getModule = class MrcModule extends ServerModule {
constructor() {
super();
this.log = Log.child( { server : 'MRC' } );
const config = Config();
this.mrcConnectOpts = {
host : config.chatServers.mrc.serverHostname || 'mrc.bottomlessabyss.net',
port : config.chatServers.mrc.serverPort || 5000,
retryDelay : config.chatServers.mrc.retryDelay || 10000
};
}
_connectionHandler() {
const config = Config();
const boardName = config.general.prettyBoardName || config.general.boardName;
const enigmaVersion = 'ENiGMA½-BBS_' + require('../../../package.json').version;
const handshake = `${boardName}~${enigmaVersion}/${os.platform()}.${os.arch()}/${protocolVersion}`;
this.log.debug({ handshake : handshake }, 'Handshaking with MRC server');
this.sendRaw(handshake);
this.log.info(this.mrcConnectOpts, 'Connected to MRC server');
}
createServer(cb) {
if (!this.enabled) {
return cb(null);
}
this.connectToMrc();
this.createLocalListener();
return cb(null);
}
listen(cb) {
if (!this.enabled) {
return cb(null);
}
const config = Config();
const port = parseInt(config.chatServers.mrc.multiplexerPort);
if(isNaN(port)) {
this.log.warn( { port : config.chatServers.mrc.multiplexerPort, server : ModuleInfo.name }, 'Invalid port' );
return cb(Errors.Invalid(`Invalid port: ${config.chatServers.mrc.multiplexerPort}`));
}
Log.info( { server : ModuleInfo.name, port : config.chatServers.mrc.multiplexerPort }, 'MRC multiplexer starting up');
return this.server.listen(port, cb);
}
/**
* Handles connecting to to the MRC server
*/
connectToMrc() {
const self = this;
// create connection to MRC server
this.mrcClient = net.createConnection(this.mrcConnectOpts, self._connectionHandler.bind(self));
this.mrcClient.requestedDisconnect = false;
// do things when we get data from MRC central
let buffer = new Buffer.from('');
function handleData(chunk) {
if(_.isString(chunk)) {
buffer += chunk;
} else {
buffer = Buffer.concat([buffer, chunk]);
}
let lines = buffer.toString().split(lineDelimiter);
if (lines.pop()) {
// if buffer is not ended with \r\n, there's more chunks.
return;
} else {
// else, initialize the buffer.
buffer = new Buffer.from('');
}
lines.forEach( line => {
if (line.length) {
let message = self.parseMessage(line);
if (message) {
self.receiveFromMRC(message);
}
}
});
}
this.mrcClient.on('data', (data) => {
handleData(data);
});
this.mrcClient.on('end', () => {
this.log.info(this.mrcConnectOpts, 'Disconnected from MRC server');
});
this.mrcClient.on('close', () => {
if (this.mrcClient && this.mrcClient.requestedDisconnect)
return;
this.log.info(this.mrcConnectOpts, 'Disconnected from MRC server, reconnecting');
this.log.debug('Waiting ' + this.mrcConnectOpts.retryDelay + 'ms before retrying');
setTimeout(function() {
self.connectToMrc();
}, this.mrcConnectOpts.retryDelay);
});
this.mrcClient.on('error', err => {
this.log.info( { error : err.message }, 'MRC server error');
});
}
createLocalListener() {
// start a local server for clients to connect to
this.server = net.createServer( socket => {
socket.setEncoding('ascii');
socket.on('data', data => {
// split on \n to deal with getting messages in batches
data.toString().split(lineDelimiter).forEach( item => {
if (item == '') return;
// save username with socket
if(item.startsWith('--DUDE-ITS--')) {
connectedSockets.add(socket);
socket.username = item.split('|')[1];
Log.debug( { server : 'MRC', user: socket.username } , 'User connected');
} else {
this.receiveFromClient(socket.username, item);
}
});
});
socket.on('end', function() {
connectedSockets.delete(socket);
});
socket.on('error', err => {
if('ECONNRESET' !== err.code) { // normal
this.log.error( { error: err.message }, 'MRC error' );
}
});
});
}
get enabled() {
return _.get(Config(), 'chatServers.mrc.enabled', false) && this.isConfigured();
}
isConfigured() {
const config = Config();
return _.isNumber(_.get(config, 'chatServers.mrc.multiplexerPort'));
}
/**
* Sends received messages to local clients
*/
sendToClient(message) {
connectedSockets.forEach( (client) => {
if (message.to_user == '' || message.to_user == client.username || message.to_user == 'CLIENT' || message.from_user == client.username || message.to_user == 'NOTME' ) {
// this.log.debug({ server : 'MRC', username : client.username, message : message }, 'Forwarding message to connected user');
client.write(JSON.stringify(message) + '\n');
}
});
}
/**
* Processes messages received from the central MRC server
*/
receiveFromMRC(message) {
const config = Config();
const siteName = slugify(config.general.boardName);
if (message.from_user == 'SERVER' && message.body == 'HELLO') {
// reply with extra bbs info
this.sendToMrcServer('CLIENT', '', 'SERVER', 'ALL', '', `INFOSYS:${StatLog.getSystemStat(SysProps.SysOpUsername)}`);
this.sendToMrcServer('CLIENT', '', 'SERVER', 'ALL', '', `INFOWEB:${config.general.website}`);
this.sendToMrcServer('CLIENT', '', 'SERVER', 'ALL', '', `INFOTEL:${config.general.telnetHostname}`);
this.sendToMrcServer('CLIENT', '', 'SERVER', 'ALL', '', `INFOSSH:${config.general.sshHostname}`);
this.sendToMrcServer('CLIENT', '', 'SERVER', 'ALL', '', `INFODSC:${config.general.description}`);
} else if (message.from_user == 'SERVER' && message.body.toUpperCase() == 'PING') {
// reply to heartbeat
this.sendToMrcServer('CLIENT', '', 'SERVER', 'ALL', '', `IMALIVE:${siteName}`);
} else {
// if not a heartbeat, and we have clients then we need to send something to them
this.sendToClient(message);
}
}
/**
* Takes an MRC message and parses it into something usable
*/
parseMessage(line) {
const [from_user, from_site, from_room, to_user, to_site, to_room, body ] = line.split('~');
// const msg = line.split('~');
// if (msg.length < 7) {
// return;
// }
return { from_user, from_site, from_room, to_user, to_site, to_room, body };
}
/**
* Receives a message from a local client and sanity checks before sending on to the central MRC server
*/
receiveFromClient(username, message) {
try {
message = JSON.parse(message);
} catch (e) {
Log.debug({ server : 'MRC', user : username, message : message }, 'Dodgy message received from client');
}
this.sendToMrcServer(message.from_user, message.from_room, message.to_user, message.to_site, message.to_room, message.body);
}
/**
* Converts a message back into the MRC format and sends it to the central MRC server
*/
sendToMrcServer(fromUser, fromRoom, toUser, toSite, toRoom, messageBody) {
const config = Config();
const siteName = slugify(config.general.boardName);
const line = [
fromUser,
siteName,
sanitiseRoomName(fromRoom),
sanitiseName(toUser || ''),
sanitiseName(toSite || ''),
sanitiseRoomName(toRoom || ''),
sanitiseMessage(messageBody)
].join('~') + '~';
// Log.debug({ server : 'MRC', data : line }, 'Sending data');
this.sendRaw(line);
}
sendRaw(message) {
// optionally log messages here
this.mrcClient.write(message + '\n');
}
};
/**
* User / site name must be ASCII 33-125, no MCI, 30 chars max, underscores
*/
function sanitiseName(str) {
return str.replace(
/\s/g, '_'
).replace(
/[^\x21-\x7D]|(\|\w\w)/g, '' // Non-printable & MCI
).substr(
0, 30
);
}
function sanitiseRoomName(message) {
return message.replace(/[^\x21-\x7D]|(\|\w\w)/g, '').substr(0, 30);
}
function sanitiseMessage(message) {
return message.replace(/[^\x20-\x7D]/g, '');
}
/**
* SLugifies the BBS name for use as an MRC "site name"
*/
function slugify(text) {
return text.toString()
.replace(/\s+/g, '_') // Replace spaces with _
.replace(/[^\w\-]+/g, '') // Remove all non-word chars
.replace(/\-\-+/g, '_') // Replace multiple - with single -
.replace(/^-+/, '') // Trim - from start of text
.replace(/-+$/, ''); // Trim - from end of text
}