src/main/resources/tunnel.js

   1
   2 /*
   3  *  Guacamole - Clientless Remote Desktop
   4  *  Copyright (C) 2010  Michael Jumper
   5  *
   6  *  This program is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU Affero General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU Affero General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Affero General Public License
  17  */
  18
  19 function GuacamoleHTTPTunnel(tunnelURL) {
  20
  21     var TUNNEL_CONNECT = tunnelURL + "?connect";
  22     var TUNNEL_READ    = tunnelURL + "?read";
  23     var TUNNEL_WRITE   = tunnelURL + "?write";
  24
  25     var connected = 0;
  26     var pollResponse = 1; // Default to polling - will be turned off automatically if not needed
  27     var instructionHandler = null;
  28
  29     var sendingMessages = 0;
  30     var outputMessageBuffer = "";
  31
  32     function sendMessage(message) {
  33
  34         // Do not attempt to send messages if not connected
  35         if (!connected)
  36             return;
  37
  38         // Add event to queue, restart send loop if finished.
  39         outputMessageBuffer += message;
  40         if (sendingMessages == 0)
  41             sendPendingMessages();
  42
  43     };
  44
  45     function sendPendingMessages() {
  46
  47         if (outputMessageBuffer.length > 0) {
  48
  49             sendingMessages = 1;
  50
  51             var message_xmlhttprequest = new XMLHttpRequest();
  52             message_xmlhttprequest.open("POST", TUNNEL_WRITE);
  53             message_xmlhttprequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  54             message_xmlhttprequest.setRequestHeader("Content-length", outputMessageBuffer.length);
  55
  56             // Once response received, send next queued event.
  57             message_xmlhttprequest.onreadystatechange = function() {
  58                 if (message_xmlhttprequest.readyState == 4)
  59                     sendPendingMessages();
  60             }
  61
  62             message_xmlhttprequest.send(outputMessageBuffer);
  63             outputMessageBuffer = ""; // Clear buffer
  64
  65         }
  66         else
  67             sendingMessages = 0;
  68
  69     }
  70
  71
  72     function handleResponse(xmlhttprequest) {
  73
  74         var interval = null;
  75         var nextRequest = null;
  76
  77         var dataUpdateEvents = 0;
  78         var instructionStart = 0;
  79         var startIndex = 0;
  80
  81         function parseResponse() {
  82
  83             // Do not handle responses if not connected
  84             if (!connected) {
  85
  86                 // Clean up interval if polling
  87                 if (interval != null)
  88                     clearInterval(interval);
  89
  90                 return;
  91             }
  92
  93             // Start next request as soon as possible
  94             if (xmlhttprequest.readyState >= 2 && nextRequest == null)
  95                 nextRequest = makeRequest();
  96
  97             // Parse stream when data is received and when complete.
  98             if (xmlhttprequest.readyState == 3 ||
  99                 xmlhttprequest.readyState == 4) {
 100
 101                 // Also poll every 30ms (some browsers don't repeatedly call onreadystatechange for new data)
 102                 if (pollResponse == 1) {
 103                     if (xmlhttprequest.readyState == 3 && interval == null)
 104                         interval = setInterval(parseResponse, 30);
 105                     else if (xmlhttprequest.readyState == 4 && interval != null)
 106                         clearInterval(interval);
 107                 }
 108
 109                 // Halt on error during request
 110                 if (xmlhttprequest.status == 0 || xmlhttprequest.status != 200) {
 111                     disconnect();
 112                     return;
 113                 }
 114
 115                 var current = xmlhttprequest.responseText;
 116                 var instructionEnd;
 117
 118                 while ((instructionEnd = current.indexOf(";", startIndex)) != -1) {
 119
 120                     // Start next search at next instruction
 121                     startIndex = instructionEnd+1;
 122
 123                     var instruction = current.substr(instructionStart,
 124                             instructionEnd - instructionStart);
 125
 126                     instructionStart = startIndex;
 127
 128                     var opcodeEnd = instruction.indexOf(":");
 129
 130                     var opcode;
 131                     var parameters;
 132                     if (opcodeEnd == -1) {
 133                         opcode = instruction;
 134                         parameters = new Array();
 135                     }
 136                     else {
 137                         opcode = instruction.substr(0, opcodeEnd);
 138                         parameters = instruction.substr(opcodeEnd+1).split(",");
 139                     }
 140
 141                     // If we're done parsing, handle the next response.
 142                     if (opcode.length == 0) {
 143
 144                         delete xmlhttprequest;
 145                         if (nextRequest)
 146                             handleResponse(nextRequest);
 147
 148                         break;
 149                     }
 150
 151                     // Call instruction handler.
 152                     if (instructionHandler != null)
 153                         instructionHandler(opcode, parameters);
 154                 }
 155
 156                 // Start search at end of string.
 157                 startIndex = current.length;
 158
 159                 delete instruction;
 160                 delete parameters;
 161
 162             }
 163
 164         }
 165
 166         // If response polling enabled, attempt to detect if still
 167         // necessary (via wrapping parseResponse())
 168         if (pollResponse == 1) {
 169             xmlhttprequest.onreadystatechange = function() {
 170
 171                 // If we receive two or more readyState==3 events,
 172                 // there is no need to poll.
 173                 if (xmlhttprequest.readyState == 3) {
 174                     dataUpdateEvents++;
 175                     if (dataUpdateEvents >= 2) {
 176                         pollResponse = 0;
 177                         xmlhttprequest.onreadystatechange = parseResponse;
 178                     }
 179                 }
 180
 181                 parseResponse();
 182             }
 183         }
 184
 185         // Otherwise, just parse
 186         else
 187             xmlhttprequest.onreadystatechange = parseResponse;
 188
 189         parseResponse();
 190
 191     }
 192
 193
 194     function makeRequest() {
 195
 196         // Download self
 197         var xmlhttprequest = new XMLHttpRequest();
 198         xmlhttprequest.open("POST", TUNNEL_READ);
 199         xmlhttprequest.send(null);
 200
 201         return xmlhttprequest;
 202
 203     }
 204
 205     function connect() {
 206
 207         // Start tunnel and connect synchronously
 208         var connect_xmlhttprequest = new XMLHttpRequest();
 209         connect_xmlhttprequest.open("POST", TUNNEL_CONNECT, false);
 210         connect_xmlhttprequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
 211         connect_xmlhttprequest.setRequestHeader("Content-length", 0);
 212         connect_xmlhttprequest.send(null);
 213
 214         // Start reading data
 215         connected = 1;
 216         handleResponse(makeRequest());
 217
 218     }
 219
 220     function disconnect() {
 221         connected = 0;
 222     }
 223
 224     // External API
 225     this.connect = connect;
 226     this.disconnect = disconnect;
 227     this.sendMessage = sendMessage;
 228     this.setInstructionHandler = function(handler) {
 229         instructionHandler = handler;
 230     }
 231
 232     this.escapeGuacamoleString = function(str) {
 233
 234         var escapedString = "";
 235
 236         for (var i=0; i<str.length; i++) {
 237
 238             var c = str.charAt(i);
 239             if (c == ",")
 240                 escapedString += "\\c";
 241             else if (c == ";")
 242                 escapedString += "\\s";
 243             else if (c == "\\")
 244                 escapedString += "\\\\";
 245             else
 246                 escapedString += c;
 247
 248         }
 249
 250         return escapedString;
 251
 252     }
 253
 254     this.unescapeGuacamoleString = function(str) {
 255
 256         var unescapedString = "";
 257
 258         for (var i=0; i<str.length; i++) {
 259
 260             var c = str.charAt(i);
 261             if (c == "\\" && i<str.length-1) {
 262
 263                 var escapeChar = str.charAt(++i);
 264                 if (escapeChar == "c")
 265                     unescapedString += ",";
 266                 else if (escapeChar == "s")
 267                     unescapedString += ";";
 268                 else if (escapeChar == "\\")
 269                     unescapedString += "\\";
 270                 else
 271                     unescapedString += "\\" + escapeChar;
 272
 273             }
 274             else
 275                 unescapedString += c;
 276
 277         }
 278
 279         return unescapedString;
 280
 281     }
 282
 283 }