From c634e03cb553e21158fddc6d4221a54aa799de79 Mon Sep 17 00:00:00 2001 From: marzavec Date: Mon, 18 Mar 2019 23:36:21 -0700 Subject: refactoring 1 of 2 --- server/src/serverLib/MainServer.js | 434 +++++++++++++++++++++++++++++++++++++ 1 file changed, 434 insertions(+) create mode 100644 server/src/serverLib/MainServer.js (limited to 'server/src/serverLib/MainServer.js') diff --git a/server/src/serverLib/MainServer.js b/server/src/serverLib/MainServer.js new file mode 100644 index 0000000..628d8ab --- /dev/null +++ b/server/src/serverLib/MainServer.js @@ -0,0 +1,434 @@ +/** + * Main websocket server handling communications and connection events + * + * Version: v2.0.0 + * Developer: Marzavec ( https://github.com/marzavec ) + * License: WTFPL ( http://www.wtfpl.net/txt/copying/ ) + * + */ + +const wsServer = require('ws').Server; +const socketReady = require('ws').OPEN; +const crypto = require('crypto'); +const ipSalt = [...Array(Math.floor(Math.random()*128)+128)].map(i=>(~~(Math.random()*36)).toString(36)).join(''); +const internalCmdKey = [...Array(Math.floor(Math.random()*128)+128)].map(i=>(~~(Math.random()*36)).toString(36)).join(''); +const RateLimiter = require('./RateLimiter'); +const pulseSpeed = 16000; // ping all clients every X ms + +class MainServer extends wsServer { + /** + * Create a HackChat server instance. + * + * @param {Object} core Reference to the global core object + */ + constructor (core) { + super({ port: core.config.websocketPort }); + + this._core = core; + this._hooks = {}; + this._police = new RateLimiter(); + this._cmdBlacklist = {}; + this._cmdKey = internalCmdKey; + + this._heartBeat = setInterval(() => this.beatHeart(), pulseSpeed); + + this.on('error', (err) => { + this.handleError('server', err); + }); + + this.on('connection', (socket, request) => { + this.newConnection(socket, request); + }); + + this.loadHooks(); + } + + /** + * Send empty `ping` frame to each client + * + */ + beatHeart () { + let targetSockets = this.findSockets({}); + + if (targetSockets.length === 0) { + return; + } + + for (let i = 0, l = targetSockets.length; i < l; i++) { + try { + if (targetSockets[i].readyState === socketReady) { + targetSockets[i].ping(); + } + } catch (e) { } + } + } + + /** + * Bind listeners for the new socket created on connection to this class + * + * @param {Object} socket New socket object + * @param {Object} request Initial headers of the new connection + */ + newConnection (socket, request) { + socket.remoteAddress = request.headers['x-forwarded-for'] || request.connection.remoteAddress; + + socket.on('message', (data) => { + this.handleData(socket, data); + }); + + socket.on('close', () => { + this.handleClose(socket); + }); + + socket.on('error', (err) => { + this.handleError(socket, err); + }); + } + + /** + * Handle incoming messages from clients, parse and check command, then hand-off + * + * @param {Object} socket Calling socket object + * @param {String} data Message sent from client + */ + handleData (socket, data) { + // Don't penalize yet, but check whether IP is rate-limited + if (this._police.frisk(socket.remoteAddress, 0)) { + this._core.commands.handleCommand(this, socket, { + cmd: 'socketreply', + cmdKey: this._cmdKey, + text: 'Your IP is being rate-limited or blocked.' + }); + + return; + } + + // Penalize here, but don't do anything about it + this._police.frisk(socket.remoteAddress, 1); + + // Ignore ridiculously large packets + if (data.length > 65536) { + return; + } + + // Start sent data verification + var payload = null; + try { + payload = JSON.parse(data); + } catch (e) { + // Client sent malformed json, gtfo + socket.close(); + } + + if (payload === null) { + return; + } + + if (typeof payload.cmd === 'undefined') { + return; + } + + if (typeof payload.cmd !== 'string') { + return; + } + + if (typeof socket.channel === 'undefined' && (payload.cmd !== 'join' && payload.cmd !== 'chat')) { + return; + } + + if (typeof this._cmdBlacklist[payload.cmd] === 'function') { + return; + } + + // Execute `in` (incoming data) hooks and process results + payload = this.executeHooks('in', socket, payload); + + if (typeof payload === 'string') { + // A hook malfunctioned, reply with error + this._core.commands.handleCommand(this, socket, { + cmd: 'socketreply', + cmdKey: this._cmdKey, + text: payload + }); + + return; + } else if (payload === false) { + // A hook requested this data be dropped + return; + } + + // Finished verification & hooks, pass to command modules + this._core.commands.handleCommand(this, socket, payload); + } + + /** + * Handle socket close from clients + * + * @param {Object} socket Closing socket object + */ + handleClose (socket) { + this._core.commands.handleCommand(this, socket, { + cmd: 'disconnect', + cmdKey: this._cmdKey + }); + } + + /** + * "Handle" server or socket errors + * + * @param {Object||String} socket Calling socket object, or 'server' + * @param {String} err The sad stuff + */ + handleError (socket, err) { + console.log(`Server error: ${err}`); + } + + /** + * Send data payload to specific socket/client + * + * @param {Object} payload Object to convert to json for transmission + * @param {Object} socket The target client + */ + send (payload, socket) { + // Add timestamp to command + payload.time = Date.now(); + + // Execute `in` (incoming data) hooks and process results + payload = this.executeHooks('out', socket, payload); + + if (typeof payload === 'string') { + // A hook malfunctioned, reply with error + this._core.commands.handleCommand(this, socket, { + cmd: 'socketreply', + cmdKey: this._cmdKey, + text: payload + }); + + return; + } else if (payload === false) { + // A hook requested this data be dropped + return; + } + + try { + if (socket.readyState === socketReady) { + socket.send(JSON.stringify(payload)); + } + } catch (e) { } + } + + /** + * Overload function for `this.send()` + * + * @param {Object} payload Object to convert to json for transmission + * @param {Object} socket The target client + */ + reply (payload, socket) { + this.send(payload, socket); + } + + /** + * Finds sockets/clients that meet the filter requirements, then passes the data to them + * + * @param {Object} payload Object to convert to json for transmission + * @param {Object} filter see `this.findSockets()` + */ + broadcast (payload, filter) { + let targetSockets = this.findSockets(filter); + + if (targetSockets.length === 0) { + return false; + } + + for (let i = 0, l = targetSockets.length; i < l; i++) { + this.send(payload, targetSockets[i]); + } + + return true; + } + + /** + * Finds sockets/clients that meet the filter requirements, returns result as array + * + * @param {Object} data Object to convert to json for transmission + * @param {Object} filter The socket must of equal or greater attribs matching `filter` + * = {} // matches all + * = { channel: 'programming' } // matches any socket where (`socket.channel` === 'programming') + * = { channel: 'programming', nick: 'Marzavec' } // matches any socket where (`socket.channel` === 'programming' && `socket.nick` === 'Marzavec') + */ + findSockets (filter) { + let filterAttribs = Object.keys(filter); + let reqCount = filterAttribs.length; + let curMatch; + let matches = []; + for ( let socket of this.clients ) { + curMatch = 0; + + for (let i = 0; i < reqCount; i++) { + if (typeof socket[filterAttribs[i]] !== 'undefined') { + switch(typeof filter[filterAttribs[i]]) { + case 'object': { + if (Array.isArray(filter[filterAttribs[i]])) { + if (filter[filterAttribs[i]].indexOf(socket[filterAttribs[i]]) !== -1) { + curMatch++; + } + } else { + if (socket[filterAttribs[i]] === filter[filterAttribs[i]]) { + curMatch++; + } + } + break; + } + + case 'function': { + if (filter[filterAttribs[i]](socket[filterAttribs[i]])) { + curMatch++; + } + break; + } + + default: { + if (socket[filterAttribs[i]] === filter[filterAttribs[i]]) { + curMatch++; + } + break; + } + } + } + } + + if (curMatch === reqCount) { + matches.push(socket); + } + } + + return matches; + } + + /** + * Hashes target socket's remote address using non-static variable length salt + * encodes and shortens the output, returns that value + * + * @param {Object||String} target Either the target socket or ip as string + */ + getSocketHash (target) { + let sha = crypto.createHash('sha256'); + + if (typeof target === 'string') { + sha.update(target + ipSalt); + } else { + sha.update(target.remoteAddress + ipSalt); + } + + return sha.digest('base64').substr(0, 15); + } + + /** + * (Re)loads all command module hooks, then sorts their order of operation by + * priority, ascending (0 being highest priority) + * + */ + loadHooks () { + // clear current hooks (if any) + this.clearHooks(); + // notify each module to register their hooks (if any) + this._core.commands.initCommandHooks(this); + + if (typeof this._hooks['in'] !== 'undefined') { + // start sorting, with incoming first + let curHooks = [ ...this._hooks['in'].keys() ]; + let hookObj = []; + for (let i = 0, j = curHooks.length; i < j; i++) { + hookObj = this._hooks['in'].get(curHooks[i]); + hookObj.sort( (h1, h2) => h1.priority - h2.priority ); + this._hooks['in'].set(hookObj); + } + } + + if (typeof this._hooks['out'] !== 'undefined') { + // then outgoing + curHooks = [ ...this._hooks['out'].keys() ]; + for (let i = 0, j = curHooks.length; i < j; i++) { + hookObj = this._hooks['out'].get(curHooks[i]); + hookObj.sort( (h1, h2) => h1.priority - h2.priority ); + this._hooks['out'].set(hookObj); + } + } + } + + /** + * Adds a target function to an array of hooks. Hooks are executed either before + * processing user input (`in`) or before sending data back to the client (`out`) + * and allows a module to modify each payload before moving forward + * + * @param {String} type The type of event, typically `in` (incoming) or `out` (outgoing) + * @param {String} command Should match the desired `cmd` attrib of the payload + * @param {Function} hookFunction Target function to execute, should accept `server`, `socket` and `payload` as parameters + * @param {Number} priority Execution priority, hooks with priority 1 will be executed before hooks with priority 200 for example + */ + registerHook (type, command, hookFunction, priority) { + if (typeof priority === 'undefined') { + priority = 25; + } + + if (typeof this._hooks[type] === 'undefined') { + this._hooks[type] = new Map(); + } + + if (!this._hooks[type].has(command)) { + this._hooks[type].set(command, []); + } + + this._hooks[type].get(command).push({ + run: hookFunction, + priority: priority + }); + } + + /** + * Loops through registered hooks & processes the results. Returned data will + * be one of three possiblities: + * A payload (modified or not) that will continue through the data flow + * A boolean false to indicate halting the data through flow + * A string which indicates an error occured in executing the hook + * + * @param {String} type The type of event, typically `in` (incoming) or `out` (outgoing) + * @param {Object} socket Either the target client or the client triggering the hook (depending on `type`) + * @param {Object} payload Either incoming data from client or outgoing data (depending on `type`) + */ + executeHooks (type, socket, payload) { + let command = payload.cmd; + + if (typeof this._hooks[type] !== 'undefined') { + if (this._hooks[type].has(command)) { + let hooks = this._hooks[type].get(command); + + for (let i = 0, j = hooks.length; i < j; i++) { + try { + payload = hooks[i].run(this._core, this, socket, payload); + } catch (err) { + let errText = `Hook failure, '${type}', '${command}': ${err}`; + console.log(errText); + return errText; + } + + // A hook function may choose to return false to prevent all further processing + if (payload === false) { + return false; + } + } + } + } + + return payload; + } + + /** + * Wipe server hooks to make ready for module reload calls + */ + clearHooks () { + this._hooks = {}; + } +} + +module.exports = MainServer; -- cgit v1.2.1