1 files changed, 434 insertions, 0 deletions
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;