text: /**
  * @description MeshCentral connection relay module
  * @author Ylian Saint-Hilaire
  * @copyright Intel Corporation 2018-2019
  * @license Apache-2.0
  * @version v0.0.1
  */
  
  /*jslint node: true */
  /*jshint node: true */
  /*jshint strict:false */
  /*jshint -W097 */
  /*jshint esversion: 6 */
  "use strict";
  
  module.exports.CreateMeshRelay = function (parent, ws, req, domain, user, cookie) {
      var obj = {};
      obj.ws = ws;
      obj.req = req;
      obj.peer = null;
      obj.user = user;
      obj.cookie = cookie;
      obj.parent = parent;
      obj.id = req.query.id;
      obj.remoteaddr = obj.ws._socket.remoteAddress;
      obj.domain = domain;
      if (obj.remoteaddr.startsWith('::ffff:')) { obj.remoteaddr = obj.remoteaddr.substring(7); }
      obj.parent.relaySessionCount++;
  
      // Mesh Rights
      const MESHRIGHT_EDITMESH = 1;
      const MESHRIGHT_MANAGEUSERS = 2;
      const MESHRIGHT_MANAGECOMPUTERS = 4;
      const MESHRIGHT_REMOTECONTROL = 8;
      const MESHRIGHT_AGENTCONSOLE = 16;
      const MESHRIGHT_SERVERFILES = 32;
      const MESHRIGHT_WAKEDEVICE = 64;
      const MESHRIGHT_SETNOTES = 128;
      const MESHRIGHT_REMOTEVIEW = 256;
  
      // Site rights
      const SITERIGHT_SERVERBACKUP = 1;
      const SITERIGHT_MANAGEUSERS = 2;
      const SITERIGHT_SERVERRESTORE = 4;
      const SITERIGHT_FILEACCESS = 8;
      const SITERIGHT_SERVERUPDATE = 16;
      const SITERIGHT_LOCKED = 32;
  
      // Disconnect this agent
      obj.close = function (arg) {
          if ((arg == 1) || (arg == null)) { try { obj.ws.close(); obj.parent.parent.debug(1, 'Relay: Soft disconnect (' + obj.remoteaddr + ')'); } catch (e) { console.log(e); } } // Soft close, close the websocket
          if (arg == 2) { try { obj.ws._socket._parent.end(); obj.parent.parent.debug(1, 'Relay: Hard disconnect (' + obj.remoteaddr + ')'); } catch (e) { console.log(e); } } // Hard close, close the TCP socket
      };
  
      obj.sendAgentMessage = function (command, userid, domainid) {
          var rights;
          if (command.nodeid == null) return false;
          var user = obj.parent.users[userid];
          if (user == null) return false;
          var splitnodeid = command.nodeid.split('/');
          // Check that we are in the same domain and the user has rights over this node.
          if ((splitnodeid[0] == 'node') && (splitnodeid[1] == domainid)) {
              // Get the user object
              // See if the node is connected
              var agent = obj.parent.wsagents[command.nodeid];
              if (agent != null) {
                  // Check if we have permission to send a message to that node
                  rights = user.links[agent.dbMeshKey];
                  if (rights != null || ((rights & 16) != 0)) { // TODO: 16 is console permission, may need more gradular permission checking
                      command.sessionid = ws.sessionId;   // Set the session id, required for responses.
                      command.rights = rights.rights;     // Add user rights flags to the message
                      delete command.nodeid;              // Remove the nodeid since it's implyed.
                      agent.send(JSON.stringify(command));
                      return true;
                  }
              } else {
                  // Check if a peer server is connected to this agent
                  var routing = obj.parent.parent.GetRoutingServerId(command.nodeid, 1); // 1 = MeshAgent routing type
                  if (routing != null) {
                      // Check if we have permission to send a message to that node
                      rights = user.links[routing.meshid];
                      if (rights != null || ((rights & 16) != 0)) { // TODO: 16 is console permission, may need more gradular permission checking
                          command.fromSessionid = ws.sessionId;   // Set the session id, required for responses.
                          command.rights = rights.rights;         // Add user rights flags to the message
                          obj.parent.parent.multiServer.DispatchMessageSingleServer(command, routing.serverid);
                          return true;
                      }
                  }
              }
          }
          return false;
      };
      
      function performRelay() {
          if (obj.id == null) { try { obj.close(); } catch (e) { } return null; } // Attempt to connect without id, drop this.
          ws._socket.setKeepAlive(true, 240000); // Set TCP keep alive
  
          // If this is a MeshMessenger session, the ID is the two userid's and authentication must match one of them.
          if (obj.id.startsWith('meshmessenger/')) {
              if ((obj.id.startsWith('meshmessenger/user/') == true) && (obj.user == null)) { try { obj.close(); } catch (e) { } return null; } // If user-to-user, both sides need to be authenticated.
              var x = obj.id.split('/'), user1 = x[1] + '/' + x[2] + '/' + x[3], user2 = x[4] + '/' + x[5] + '/' + x[6];
              if ((x[1] != 'user') && (x[4] != 'user')) { try { obj.close(); } catch (e) { } return null; } // MeshMessenger session must have at least one authenticated user
              if ((x[1] == 'user') && (x[4] == 'user')) {
                  // If this is a user-to-user session, you must be authenticated to join.
                  if ((obj.user._id != user1) && (obj.user._id != user2)) { try { obj.close(); } catch (e) { } return null; }
              } else {
                  // If only one side of the session is a user
                  // !!!!! TODO: Need to make sure that one of the two sides is the correct user. !!!!!
              }
          }
  
          // Validate that the id is valid, we only need to do this on non-authenticated sessions.
          // TODO: Figure out when this needs to be done.
          /*
          if (!parent.args.notls) {
              // Check the identifier, if running without TLS, skip this.
              var ids = obj.id.split(':');
              if (ids.length != 3) { obj.ws.close(); obj.id = null; return null; } // Invalid ID, drop this.
              if (parent.crypto.createHmac('SHA384', parent.relayRandom).update(ids[0] + ':' + ids[1]).digest('hex') != ids[2]) { obj.ws.close(); obj.id = null; return null; } // Invalid HMAC, drop this.
              if ((Date.now() - parseInt(ids[1])) > 120000) { obj.ws.close(); obj.id = null; return null; } // Expired time, drop this.
              obj.id = ids[0];
          }
          */
  
          // Check the peer connection status
          {
              var relayinfo = parent.wsrelays[obj.id];
              if (relayinfo) {
                  if (relayinfo.state == 1) {
                      // Check that at least one connection is authenticated
                      if ((obj.authenticated != true) && (relayinfo.peer1.authenticated != true)) {
                          obj.id = null;
                          obj.ws.close();
                          obj.parent.parent.debug(1, 'Relay without-auth: ' + obj.id + ' (' + obj.remoteaddr + ')');
                          return null;
                      }
  
                      // Connect to peer
                      obj.peer = relayinfo.peer1;
                      obj.peer.peer = obj;
                      relayinfo.peer2 = obj;
                      relayinfo.state = 2;
                      obj.ws.send('c'); // Send connect to both peers
                      relayinfo.peer1.ws.send('c');
                      relayinfo.peer1.ws._socket.resume(); // Release the traffic
                      relayinfo.peer2.ws._socket.resume(); // Release the traffic
  
                      relayinfo.peer1.ws.peer = relayinfo.peer2.ws;
                      relayinfo.peer2.ws.peer = relayinfo.peer1.ws;
  
                      obj.parent.parent.debug(1, 'Relay connected: ' + obj.id + ' (' + obj.remoteaddr + ' --> ' + obj.peer.remoteaddr + ')');
                  } else {
                      // Connected already, drop (TODO: maybe we should re-connect?)
                      obj.id = null;
                      obj.ws.close();
                      obj.parent.parent.debug(1, 'Relay duplicate: ' + obj.id + ' (' + obj.remoteaddr + ')');
                      return null;
                  }
              } else {
                  // Wait for other relay connection
                  ws._socket.pause(); // Hold traffic until the other connection
                  parent.wsrelays[obj.id] = { peer1: obj, state: 1 };
                  obj.parent.parent.debug(1, 'Relay holding: ' + obj.id + ' (' + obj.remoteaddr + ') ' + (obj.authenticated ? 'Authenticated' : ''));
  
                  // Check if a peer server has this connection
                  if (parent.parent.multiServer != null) {
                      var rsession = obj.parent.wsPeerRelays[obj.id];
                      if ((rsession != null) && (rsession.serverId > obj.parent.parent.serverId)) {
                          // We must initiate the connection to the peer
                          parent.parent.multiServer.createPeerRelay(ws, req, rsession.serverId, req.session.userid);
                          delete parent.wsrelays[obj.id];
                      } else {
                          // Send message to other peers that we have this connection
                          parent.parent.multiServer.DispatchMessage(JSON.stringify({ action: 'relay', id: obj.id }));
                      }
                  }
              }
          }
      }
  
      ws.flushSink = function () { try { ws._socket.resume(); } catch (ex) { console.log(ex); } };
  
      // When data is received from the mesh relay web socket
      ws.on('message', function (data) {
          //console.log(typeof data, data.length);
          if (this.peer != null) {
              //if (typeof data == 'string') { console.log('Relay: ' + data); } else { console.log('Relay:' + data.length + ' byte(s)'); }
              try {
                  this._socket.pause();
                  this.peer.send(data, ws.flushSink);
              } catch (ex) { console.log(ex); }
          }
      });
  
      // If error, close both sides of the relay.
      ws.on('error', function (err) {
          obj.parent.relaySessionErrorCount++;
          console.log('Relay error from ' + obj.remoteaddr + ', ' + err.toString().split('\r')[0] + '.');
          closeBothSides();
      });
  
      // If the relay web socket is closed, close both sides.
      ws.on('close', function (req) {
          obj.parent.relaySessionCount--;
          closeBothSides();
      });
  
      // Close both our side and the peer side.
      function closeBothSides() {
          if (obj.id != null) {
              var relayinfo = parent.wsrelays[obj.id];
              if (relayinfo != null) {
                  if (relayinfo.state == 2) {
                      // Disconnect the peer
                      var peer = (relayinfo.peer1 == obj) ? relayinfo.peer2 : relayinfo.peer1;
                      obj.parent.parent.debug(1, 'Relay disconnect: ' + obj.id + ' (' + obj.remoteaddr + ' --> ' + peer.remoteaddr + ')');
                      peer.id = null;
                      try { peer.ws.close(); } catch (e) { } // Soft disconnect
                      try { peer.ws._socket._parent.end(); } catch (e) { } // Hard disconnect
                  } else {
                      obj.parent.parent.debug(1, 'Relay disconnect: ' + obj.id + ' (' + obj.remoteaddr + ')');
                  }
                  delete parent.wsrelays[obj.id];
              }
              obj.peer = null;
              obj.id = null;
          }
      }
  
      // Mark this relay session as authenticated if this is the user end.
      obj.authenticated = (obj.user != null);
      if (obj.authenticated) {
          // Kick off the routing, if we have agent routing instructions, process them here.
          // Routing instructions can only be given by a authenticated user
          if ((obj.cookie != null) && (obj.cookie.nodeid != null) && (obj.cookie.tcpport != null) && (obj.cookie.domainid != null)) {
              // We have routing instructions in the cookie, but first, check user access for this node.
              obj.parent.db.Get(obj.cookie.nodeid, function (err, docs) {
                  if (docs.length == 0) { console.log('ERR: Node not found'); try { obj.close(); } catch (e) { } return; } // Disconnect websocket
                  var node = docs[0];
  
                  // Check if this user has permission to manage this computer
                  var meshlinks = obj.user.links[node.meshid];
                  if ((!meshlinks) || (!meshlinks.rights) || ((meshlinks.rights & MESHRIGHT_REMOTECONTROL) == 0)) { console.log('ERR: Access denied (2)'); try { obj.close(); } catch (e) { } return; }
  
                  // Send connection request to agent
                  if (obj.id == undefined) { obj.id = ('' + Math.random()).substring(2); } // If there is no connection id, generate one.
                  var command = { nodeid: obj.cookie.nodeid, action: 'msg', type: 'tunnel', value: '*/meshrelay.ashx?id=' + obj.id, tcpport: obj.cookie.tcpport, tcpaddr: obj.cookie.tcpaddr };
                  obj.parent.parent.debug(1, 'Relay: Sending agent tunnel command: ' + JSON.stringify(command));
                  if (obj.sendAgentMessage(command, obj.user._id, obj.cookie.domainid) == false) { obj.id = null; obj.parent.parent.debug(1, 'Relay: Unable to contact this agent (' + obj.remoteaddr + ')'); }
                  performRelay();
              });
              return obj;
          } else if ((req.query.nodeid != null) && (req.query.tcpport != null)) {
              // We have routing instructions in the URL arguments, but first, check user access for this node.
              obj.parent.db.Get(req.query.nodeid, function (err, docs) {
                  if (docs.length == 0) { console.log('ERR: Node not found'); try { obj.close(); } catch (e) { } return; } // Disconnect websocket
                  var node = docs[0];
  
                  // Check if this user has permission to manage this computer
                  var meshlinks = obj.user.links[node.meshid];
                  if ((!meshlinks) || (!meshlinks.rights) || ((meshlinks.rights & MESHRIGHT_REMOTECONTROL) == 0)) { console.log('ERR: Access denied (2)'); try { obj.close(); } catch (e) { } return; }
  
                  // Send connection request to agent
                  if (obj.id == null) { obj.id = ('' + Math.random()).substring(2); } // If there is no connection id, generate one.
                  var command = { nodeid: req.query.nodeid, action: 'msg', type: 'tunnel', value: '*/meshrelay.ashx?id=' + obj.id, tcpport: req.query.tcpport, tcpaddr: ((req.query.tcpaddr == null) ? '127.0.0.1' : req.query.tcpaddr) };
                  obj.parent.parent.debug(1, 'Relay: Sending agent tunnel command: ' + JSON.stringify(command));
                  if (obj.sendAgentMessage(command, obj.user._id, obj.domain.id) == false) { obj.id = null; obj.parent.parent.debug(1, 'Relay: Unable to contact this agent (' + obj.remoteaddr + ')'); }
                  performRelay();
              });
              return obj;
          }
      }
  
      // If this is not an authenticated session, or the session does not have routing instructions, just go ahead an connect to existing session.
      performRelay();
      return obj;
  };
  