mod/chat/chatd.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Chat daemon
  19  *
  20  * @package    mod_chat
  21  * @copyright  1999 onwards Martin Dougiamas  {@link http://moodle.com}
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 define('CLI_SCRIPT', true);
  26
  27 require(dirname(dirname(dirname(__FILE__))).'/config.php');
  28 require_once($CFG->dirroot . '/mod/chat/lib.php');
  29
  30 // Browser quirks.
  31 define('QUIRK_CHUNK_UPDATE', 0x0001);
  32
  33 // Connection telltale.
  34 define('CHAT_CONNECTION',           0x10);
  35 // Connections: Incrementing sequence, 0x10 to 0x1f.
  36 define('CHAT_CONNECTION_CHANNEL',   0x11);
  37
  38 // Sidekick telltale.
  39 define('CHAT_SIDEKICK',             0x20);
  40 // Sidekicks: Incrementing sequence, 0x21 to 0x2f.
  41 define('CHAT_SIDEKICK_USERS',       0x21);
  42 define('CHAT_SIDEKICK_MESSAGE',     0x22);
  43 define('CHAT_SIDEKICK_BEEP',        0x23);
  44
  45 $phpversion = phpversion();
  46 echo 'Moodle chat daemon v1.0 on PHP '.$phpversion."\n\n";
  47
  48 // Set up all the variables we need.
  49
  50 // The $CFG variables are now defined in database by chat/lib.php.
  51
  52 $_SERVER['PHP_SELF']        = 'dummy';
  53 $_SERVER['SERVER_NAME']     = 'dummy';
  54 $_SERVER['HTTP_USER_AGENT'] = 'dummy';
  55
  56 $_SERVER['SERVER_NAME'] = $CFG->chat_serverhost;
  57 $_SERVER['PHP_SELF']    = "http://$CFG->chat_serverhost:$CFG->chat_serverport/mod/chat/chatd.php";
  58
  59 core_php_time_limit::raise(0);
  60 error_reporting(E_ALL);
  61
  62 function chat_empty_connection() {
  63     return array('sid' => null, 'handle' => null, 'ip' => null, 'port' => null, 'groupid' => null);
  64 }
  65
  66 class ChatConnection {
  67     // Chat-related info.
  68     public $sid  = null;
  69     public $type = null;
  70
  71     // PHP-level info.
  72     public $handle = null;
  73
  74     // TCP/IP.
  75     public $ip     = null;
  76     public $port   = null;
  77
  78     public function __construct($resource) {
  79         $this->handle = $resource;
  80         @socket_getpeername($this->handle, $this->ip, $this->port);
  81     }
  82 }
  83
  84 class ChatDaemon {
  85     public $_resetsocket       = false;
  86     public $_readytogo         = false;
  87     public $_logfile           = false;
  88     public $_trace_to_console  = true;
  89     public $_trace_to_stdout   = true;
  90     public $_logfile_name      = 'chatd.log';
  91     public $_last_idle_poll    = 0;
  92
  93     public $connectionsunidentified  = array(); // Connections not identified yet.
  94     public $connectionsside = array(); // Sessions with sidekicks waiting for the main connection to be processed.
  95     public $connectionshalf = array(); // Sessions that have valid connections but not all of them.
  96     public $connectionssets = array(); // Sessions with complete connection sets.
  97     public $setsinfo = array(); // Keyed by sessionid exactly like conn_sets, one of these for each of those.
  98     public $chatrooms = array(); // Keyed by chatid, holding arrays of data.
  99
 100     // IMPORTANT: $connectionssets, $setsinfo and $chatrooms must remain synchronized!
 101     //            Pay extra attention when you write code that affects any of them!
 102
 103     public function __construct() {
 104         $this->_trace_level         = E_ALL ^ E_USER_NOTICE;
 105         $this->_pcntl_exists        = function_exists('pcntl_fork');
 106         $this->_time_rest_socket    = 20;
 107         $this->_beepsoundsrc        = $GLOBALS['CFG']->wwwroot.'/mod/chat/beep.wav';
 108         $this->_freq_update_records = 20;
 109         $this->_freq_poll_idle_chat = $GLOBALS['CFG']->chat_old_ping;
 110         $this->_stdout = fopen('php://stdout', 'w');
 111         if ($this->_stdout) {
 112             // Avoid double traces for everything.
 113             $this->_trace_to_console = false;
 114         }
 115     }
 116
 117     public function error_handler ($errno, $errmsg, $filename, $linenum, $vars) {
 118         // Checks if an error needs to be suppressed due to @.
 119         if (error_reporting() != 0) {
 120             $this->trace($errmsg.' on line '.$linenum, $errno);
 121         }
 122         return true;
 123     }
 124
 125     public function poll_idle_chats($now) {
 126         $this->trace('Polling chats to detect disconnected users');
 127         if (!empty($this->chatrooms)) {
 128             foreach ($this->chatrooms as $chatid => $chatroom) {
 129                 if (!empty($chatroom['users'])) {
 130                     foreach ($chatroom['users'] as $sessionid => $userid) {
 131                         // We will be polling each user as required.
 132                         $this->trace('...shall we poll '.$sessionid.'?');
 133                         if ($this->sets_info[$sessionid]['chatuser']->lastmessageping < $this->_last_idle_poll) {
 134                             $this->trace('YES!');
 135                             // This user hasn't been polled since his last message.
 136                             $result = $this->write_data($this->conn_sets[$sessionid][CHAT_CONNECTION_CHANNEL], '<!-- poll -->');
 137                             if ($result === false) {
 138                                 // User appears to have disconnected.
 139                                 $this->disconnect_session($sessionid);
 140                             }
 141                         }
 142                     }
 143                 }
 144             }
 145         }
 146         $this->_last_idle_poll = $now;
 147     }
 148
 149     public function query_start() {
 150         return $this->_readytogo;
 151     }
 152
 153     public function trace($message, $level = E_USER_NOTICE) {
 154         $severity = '';
 155
 156         switch($level) {
 157             case E_USER_WARNING:
 158                 $severity = '*IMPORTANT* ';
 159                 break;
 160             case E_USER_ERROR:
 161                 $severity = ' *CRITICAL* ';
 162                 break;
 163             case E_NOTICE:
 164             case E_WARNING:
 165                 $severity = ' *CRITICAL* [php] ';
 166                 break;
 167         }
 168
 169         $date = date('[Y-m-d H:i:s] ');
 170         $message = $date.$severity.$message."\n";
 171
 172         if ($this->_trace_level & $level) {
 173             // It is accepted for output.
 174
 175             // Error-class traces go to STDERR too.
 176             if ($level & E_USER_ERROR) {
 177                 fwrite(STDERR, $message);
 178             }
 179
 180             // Emit the message to wherever we should.
 181             if ($this->_trace_to_stdout) {
 182                 fwrite($this->_stdout, $message);
 183                 fflush($this->_stdout);
 184             }
 185             if ($this->_trace_to_console) {
 186                 echo $message;
 187                 flush();
 188             }
 189             if ($this->_logfile) {
 190                 fwrite($this->_logfile, $message);
 191                 fflush($this->_logfile);
 192             }
 193         }
 194     }
 195
 196     public function write_data($connection, $text) {
 197         $written = @socket_write($connection, $text, strlen($text));
 198         if ($written === false) {
 199             return false;
 200         }
 201         return true;
 202     }
 203
 204     public function user_lazy_update($sessionid) {
 205         global $DB;
 206
 207         if (empty($this->sets_info[$sessionid])) {
 208             $this->trace('user_lazy_update() called for an invalid SID: '.$sessionid, E_USER_WARNING);
 209             return false;
 210         }
 211
 212         $now = time();
 213
 214         // We 'll be cheating a little, and NOT updating the record data as
 215         // often as we can, so that we save on DB queries (imagine MANY users).
 216         if ($now - $this->sets_info[$sessionid]['lastinfocommit'] > $this->_freq_update_records) {
 217             // Commit to permanent storage.
 218             $this->sets_info[$sessionid]['lastinfocommit'] = $now;
 219             $DB->update_record('chat_users', $this->sets_info[$sessionid]['chatuser']);
 220         }
 221         return true;
 222     }
 223
 224     public function get_user_window($sessionid) {
 225         global $CFG, $OUTPUT;
 226
 227         static $str;
 228
 229         $info = &$this->sets_info[$sessionid];
 230
 231         $timenow = time();
 232
 233         if (empty($str)) {
 234             $str->idle  = get_string("idle", "chat");
 235             $str->beep  = get_string("beep", "chat");
 236             $str->day   = get_string("day");
 237             $str->days  = get_string("days");
 238             $str->hour  = get_string("hour");
 239             $str->hours = get_string("hours");
 240             $str->min   = get_string("min");
 241             $str->mins  = get_string("mins");
 242             $str->sec   = get_string("sec");
 243             $str->secs  = get_string("secs");
 244             $str->years = get_string('years');
 245         }
 246
 247         ob_start();
 248         $refreshinval = $CFG->chat_refresh_userlist * 1000;
 249         echo <<<EOD
 250         <html><head>
 251         <meta http-equiv="refresh" content="$refreshinval">
 252         <style type="text/css"> img{border:0} </style>
 253         <script type="text/javascript">
 254         //<![CDATA[
 255         function openpopup(url,name,options,fullscreen) {
 256             fullurl = "$CFG->wwwroot" + url;
 257             windowobj = window.open(fullurl,name,options);
 258             if (fullscreen) {
 259                 windowobj.moveTo(0,0);
 260                 windowobj.resizeTo(screen.availWidth,screen.availHeight);
 261             }
 262             windowobj.focus();
 263             return false;
 264         }
 265         //]]>
 266         </script></head><body><table><tbody>
 267 EOD;
 268
 269         // Get the users from that chatroom.
 270         $users = $this->chatrooms[$info['chatid']]['users'];
 271
 272         foreach ($users as $usersessionid => $userid) {
 273             // Fetch each user's sessionid and then the rest of his data from $this->sets_info.
 274             $userinfo = $this->sets_info[$usersessionid];
 275
 276             $lastping = $timenow - $userinfo['chatuser']->lastmessageping;
 277
 278             echo '<tr><td width="35">';
 279
 280             $link = '/user/view.php?id='.$userinfo['user']->id.'&course='.$userinfo['courseid'];
 281             $anchortagcontents = $OUTPUT->user_picture($userinfo['user'], array('courseid' => $userinfo['courseid']));
 282
 283             $action = new popup_action('click', $link, 'user'.$userinfo['chatuser']->id);
 284             $anchortag = $OUTPUT->action_link($link, $anchortagcontents, $action);
 285
 286             echo $anchortag;
 287             echo "</td><td valign=\"center\">";
 288             echo "<p><font size=\"1\">";
 289             echo fullname($userinfo['user'])."<br />";
 290             echo "<font color=\"#888888\">$str->idle: ".format_time($lastping, $str)."</font> ";
 291             echo '<a target="empty" href="http://'.$CFG->chat_serverhost.':'.$CFG->chat_serverport.
 292                  '/?win=beep&amp;beep='.$userinfo['user']->id.
 293                  '&chat_sid='.$sessionid.'">'.$str->beep."</a>\n";
 294             echo "</font></p>";
 295             echo "<td></tr>";
 296         }
 297
 298         echo '</tbody></table>';
 299         echo "</body>\n</html>\n";
 300
 301         return ob_get_clean();
 302
 303     }
 304
 305     public function new_ufo_id() {
 306         static $id = 0;
 307         if ($id++ === 0x1000000) { // Cycling very very slowly to prevent overflow.
 308             $id = 0;
 309         }
 310         return $id;
 311     }
 312
 313     public function process_sidekicks($sessionid) {
 314         if (empty($this->conn_side[$sessionid])) {
 315             return true;
 316         }
 317         foreach ($this->conn_side[$sessionid] as $sideid => $sidekick) {
 318             // TODO: is this late-dispatch working correctly?
 319             $this->dispatch_sidekick($sidekick['handle'], $sidekick['type'], $sessionid, $sidekick['customdata']);
 320             unset($this->conn_side[$sessionid][$sideid]);
 321         }
 322         return true;
 323     }
 324
 325     public function dispatch_sidekick($handle, $type, $sessionid, $customdata) {
 326         global $CFG, $DB;
 327
 328         switch($type) {
 329             case CHAT_SIDEKICK_BEEP:
 330
 331                 // Incoming beep.
 332                 $msg = new stdClass;
 333                 $msg->chatid    = $this->sets_info[$sessionid]['chatid'];
 334                 $msg->userid    = $this->sets_info[$sessionid]['userid'];
 335                 $msg->groupid   = $this->sets_info[$sessionid]['groupid'];
 336                 $msg->system    = 0;
 337                 $msg->message   = 'beep '.$customdata['beep'];
 338                 $msg->timestamp = time();
 339
 340                 // Commit to DB.
 341                 chat_send_chatmessage($this->sets_info[$sessionid]['chatuser'], $msg->message, false,
 342                     $this->sets_info[$sessionid]['cm']);
 343
 344                 // OK, now push it out to all users.
 345                 $this->message_broadcast($msg, $this->sets_info[$sessionid]['user']);
 346
 347                 // Update that user's lastmessageping.
 348                 $this->sets_info[$sessionid]['chatuser']->lastping        = $msg->timestamp;
 349                 $this->sets_info[$sessionid]['chatuser']->lastmessageping = $msg->timestamp;
 350                 $this->user_lazy_update($sessionid);
 351
 352                 // We did our work, but before slamming the door on the poor browser
 353                 // show the courtesy of responding to the HTTP request. Otherwise, some
 354                 // browsers decide to get vengeance by flooding us with repeat requests.
 355
 356                 $header  = "HTTP/1.1 200 OK\n";
 357                 $header .= "Connection: close\n";
 358                 $header .= "Date: ".date('r')."\n";
 359                 $header .= "Server: Moodle\n";
 360                 $header .= "Content-Type: text/html; charset=utf-8\n";
 361                 $header .= "Last-Modified: ".gmdate("D, d M Y H:i:s")." GMT\n";
 362                 $header .= "Cache-Control: no-cache, must-revalidate\n";
 363                 $header .= "Expires: Wed, 4 Oct 1978 09:32:45 GMT\n";
 364                 $header .= "\n";
 365
 366                 // That's enough headers for one lousy dummy response.
 367                 $this->write_data($handle, $header);
 368                 // All done.
 369             break;
 370
 371             case CHAT_SIDEKICK_USERS:
 372                 // A request to paint a user window.
 373
 374                 $content = $this->get_user_window($sessionid);
 375
 376                 $header  = "HTTP/1.1 200 OK\n";
 377                 $header .= "Connection: close\n";
 378                 $header .= "Date: ".date('r')."\n";
 379                 $header .= "Server: Moodle\n";
 380                 $header .= "Content-Type: text/html; charset=utf-8\n";
 381                 $header .= "Last-Modified: ".gmdate("D, d M Y H:i:s")." GMT\n";
 382                 $header .= "Cache-Control: no-cache, must-revalidate\n";
 383                 $header .= "Expires: Wed, 4 Oct 1978 09:32:45 GMT\n";
 384                 $header .= "Content-Length: ".strlen($content)."\n";
 385
 386                 // The refresh value is 2 seconds higher than the configuration variable.
 387                 // This is because we are doing JS refreshes all the time.
 388                 // However, if the JS doesn't work for some reason, we still want to refresh once in a while.
 389                 $header .= "Refresh: ".(intval($CFG->chat_refresh_userlist) + 2).
 390                            "; url=http://$CFG->chat_serverhost:$CFG->chat_serverport/?win=users&".
 391                            "chat_sid=".$sessionid."\n";
 392                 $header .= "\n";
 393
 394                 // That's enough headers for one lousy dummy response.
 395                 $this->trace('writing users http response to handle '.$handle);
 396                 $this->write_data($handle, $header . $content);
 397
 398                 // Update that user's lastping.
 399                 $this->sets_info[$sessionid]['chatuser']->lastping = time();
 400                 $this->user_lazy_update($sessionid);
 401
 402             break;
 403
 404             case CHAT_SIDEKICK_MESSAGE:
 405                 // Incoming message.
 406
 407                 // Browser stupidity protection from duplicate messages.
 408                 $messageindex = intval($customdata['index']);
 409
 410                 if ($this->sets_info[$sessionid]['lastmessageindex'] >= $messageindex) {
 411                     // We have already broadcasted that!
 412                     break;
 413                 } else {
 414                     // Update our info.
 415                     $this->sets_info[$sessionid]['lastmessageindex'] = $messageindex;
 416                 }
 417
 418                 $msg = new stdClass;
 419                 $msg->chatid    = $this->sets_info[$sessionid]['chatid'];
 420                 $msg->userid    = $this->sets_info[$sessionid]['userid'];
 421                 $msg->groupid   = $this->sets_info[$sessionid]['groupid'];
 422                 $msg->system    = 0;
 423                 $msg->message   = urldecode($customdata['message']); // Have to undo the browser's encoding.
 424                 $msg->timestamp = time();
 425
 426                 if (empty($msg->message)) {
 427                     // Someone just hit ENTER, send them on their way.
 428                     break;
 429                 }
 430
 431                 // A slight hack to prevent malformed SQL inserts.
 432                 $origmsg = $msg->message;
 433                 $msg->message = $msg->message;
 434
 435                 // Commit to DB.
 436                 chat_send_chatmessage($this->sets_info[$sessionid]['chatuser'], $msg->message, false,
 437                     $this->sets_info[$sessionid]['cm']);
 438
 439                 // Undo the hack.
 440                 $msg->message = $origmsg;
 441
 442                 // OK, now push it out to all users.
 443                 $this->message_broadcast($msg, $this->sets_info[$sessionid]['user']);
 444
 445                 // Update that user's lastmessageping.
 446                 $this->sets_info[$sessionid]['chatuser']->lastping        = $msg->timestamp;
 447                 $this->sets_info[$sessionid]['chatuser']->lastmessageping = $msg->timestamp;
 448                 $this->user_lazy_update($sessionid);
 449
 450                 // We did our work, but before slamming the door on the poor browser
 451                 // show the courtesy of responding to the HTTP request. Otherwise, some
 452                 // browsers decide to get vengeance by flooding us with repeat requests.
 453
 454                 $header  = "HTTP/1.1 200 OK\n";
 455                 $header .= "Connection: close\n";
 456                 $header .= "Date: ".date('r')."\n";
 457                 $header .= "Server: Moodle\n";
 458                 $header .= "Content-Type: text/html; charset=utf-8\n";
 459                 $header .= "Last-Modified: ".gmdate("D, d M Y H:i:s")." GMT\n";
 460                 $header .= "Cache-Control: no-cache, must-revalidate\n";
 461                 $header .= "Expires: Wed, 4 Oct 1978 09:32:45 GMT\n";
 462                 $header .= "\n";
 463
 464                 // That's enough headers for one lousy dummy response.
 465                 $this->write_data($handle, $header);
 466
 467                 // All done.
 468             break;
 469         }
 470
 471         socket_shutdown($handle);
 472         socket_close($handle);
 473     }
 474
 475     public function promote_final($sessionid, $customdata) {
 476         global $DB;
 477
 478         if (isset($this->conn_sets[$sessionid])) {
 479             $this->trace('Set cannot be finalized: Session '.$sessionid.' is already active');
 480             return false;
 481         }
 482
 483         $chatuser = $DB->get_record('chat_users', array('sid' => $sessionid));
 484         if ($chatuser === false) {
 485             $this->dismiss_half($sessionid);
 486             return false;
 487         }
 488         $chat = $DB->get_record('chat', array('id' => $chatuser->chatid));
 489         if ($chat === false) {
 490             $this->dismiss_half($sessionid);
 491             return false;
 492         }
 493         $user = $DB->get_record('user', array('id' => $chatuser->userid));
 494         if ($user === false) {
 495             $this->dismiss_half($sessionid);
 496             return false;
 497         }
 498         $course = $DB->get_record('course', array('id' => $chat->course));
 499         if ($course === false) {
 500             $this->dismiss_half($sessionid);
 501             return false;
 502         }
 503         if (!($cm = get_coursemodule_from_instance('chat', $chat->id, $course->id))) {
 504             $this->dismiss_half($sessionid);
 505             return false;
 506         }
 507
 508         global $CHAT_HTMLHEAD_JS;
 509
 510         $this->conn_sets[$sessionid] = $this->conn_half[$sessionid];
 511
 512         // This whole thing needs to be purged of redundant info, and the
 513         // code base to follow suit. But AFTER development is done.
 514         $this->sets_info[$sessionid] = array(
 515             'lastinfocommit' => 0,
 516             'lastmessageindex' => 0,
 517             'course'    => $course,
 518             'courseid'  => $course->id,
 519             'chatuser'  => $chatuser,
 520             'chatid'    => $chat->id,
 521             'cm'        => $cm,
 522             'user'      => $user,
 523             'userid'    => $user->id,
 524             'groupid'   => $chatuser->groupid,
 525             'lang'      => $chatuser->lang,
 526             'quirks'    => $customdata['quirks']
 527         );
 528
 529         // If we know nothing about this chatroom, initialize it and add the user.
 530         if (!isset($this->chatrooms[$chat->id]['users'])) {
 531             $this->chatrooms[$chat->id]['users'] = array($sessionid => $user->id);
 532         } else {
 533             // Otherwise just add the user.
 534             $this->chatrooms[$chat->id]['users'][$sessionid] = $user->id;
 535         }
 536
 537         $header  = "HTTP/1.1 200 OK\n";
 538         $header .= "Connection: close\n";
 539         $header .= "Date: ".date('r')."\n";
 540         $header .= "Server: Moodle\n";
 541         $header .= "Content-Type: text/html; charset=utf-8\n";
 542         $header .= "Last-Modified: ".gmdate("D, d M Y H:i:s")." GMT\n";
 543         $header .= "Cache-Control: no-cache, must-revalidate\n";
 544         $header .= "Expires: Wed, 4 Oct 1978 09:32:45 GMT\n";
 545         $header .= "\n";
 546
 547         $this->dismiss_half($sessionid, false);
 548         $this->write_data($this->conn_sets[$sessionid][CHAT_CONNECTION_CHANNEL], $header . $CHAT_HTMLHEAD_JS);
 549         $this->trace('Connection accepted: '
 550                      .$this->conn_sets[$sessionid][CHAT_CONNECTION_CHANNEL]
 551                      .', SID: '
 552                      .$sessionid
 553                      .' UID: '
 554                      .$chatuser->userid
 555                      .' GID: '
 556                      .$chatuser->groupid, E_USER_WARNING);
 557
 558         // Finally, broadcast the "entered the chat" message.
 559
 560         $msg = new stdClass;
 561         $msg->chatid = $chatuser->chatid;
 562         $msg->userid = $chatuser->userid;
 563         $msg->groupid = $chatuser->groupid;
 564         $msg->system = 1;
 565         $msg->message = 'enter';
 566         $msg->timestamp = time();
 567
 568         chat_send_chatmessage($chatuser, $msg->message, true);
 569         $this->message_broadcast($msg, $this->sets_info[$sessionid]['user']);
 570
 571         return true;
 572     }
 573
 574     public function promote_ufo($handle, $type, $sessionid, $customdata) {
 575         if (empty($this->conn_ufo)) {
 576             return false;
 577         }
 578         foreach ($this->conn_ufo as $id => $ufo) {
 579             if ($ufo->handle == $handle) {
 580                 // OK, got the id of the UFO, but what is it?
 581
 582                 if ($type & CHAT_SIDEKICK) {
 583                     // Is the main connection ready?
 584                     if (isset($this->conn_sets[$sessionid])) {
 585                         // Yes, so dispatch this sidekick now and be done with it.
 586                         $this->dispatch_sidekick($handle, $type, $sessionid, $customdata);
 587                         $this->dismiss_ufo($handle, false);
 588                     } else {
 589                         // No, so put it in the waiting list.
 590                         $this->trace('sidekick waiting');
 591                         $this->conn_side[$sessionid][] = array('type' => $type, 'handle' => $handle, 'customdata' => $customdata);
 592                     }
 593                     return true;
 594                 }
 595
 596                 // If it's not a sidekick, at this point it can only be da man.
 597
 598                 if ($type & CHAT_CONNECTION) {
 599                     // This forces a new connection right now.
 600                     $this->trace('Incoming connection from '.$ufo->ip.':'.$ufo->port);
 601
 602                     // Do we have such a connection active?
 603                     if (isset($this->conn_sets[$sessionid])) {
 604                         // Yes, so regrettably we cannot promote you.
 605                         $this->trace('Connection rejected: session '.$sessionid.' is already final');
 606                         $this->dismiss_ufo($handle, true, 'Your SID was rejected.');
 607                         return false;
 608                     }
 609
 610                     // Join this with what we may have already.
 611                     $this->conn_half[$sessionid][$type] = $handle;
 612
 613                     // Do the bookkeeping.
 614                     $this->promote_final($sessionid, $customdata);
 615
 616                     // It's not a UFO anymore.
 617                     $this->dismiss_ufo($handle, false);
 618
 619                     // Dispatch waiting sidekicks.
 620                     $this->process_sidekicks($sessionid);
 621
 622                     return true;
 623                 }
 624             }
 625         }
 626         return false;
 627     }
 628
 629     public function dismiss_half($sessionid, $disconnect = true) {
 630         if (!isset($this->conn_half[$sessionid])) {
 631             return false;
 632         }
 633         if ($disconnect) {
 634             foreach ($this->conn_half[$sessionid] as $handle) {
 635                 @socket_shutdown($handle);
 636                 @socket_close($handle);
 637             }
 638         }
 639         unset($this->conn_half[$sessionid]);
 640         return true;
 641     }
 642
 643     public function dismiss_set($sessionid) {
 644         if (!empty($this->conn_sets[$sessionid])) {
 645             foreach ($this->conn_sets[$sessionid] as $handle) {
 646                 // Since we want to dismiss this, don't generate any errors if it's dead already.
 647                 @socket_shutdown($handle);
 648                 @socket_close($handle);
 649             }
 650         }
 651         $chatroom = $this->sets_info[$sessionid]['chatid'];
 652         $userid   = $this->sets_info[$sessionid]['userid'];
 653         unset($this->conn_sets[$sessionid]);
 654         unset($this->sets_info[$sessionid]);
 655         unset($this->chatrooms[$chatroom]['users'][$sessionid]);
 656         $this->trace('Removed all traces of user with session '.$sessionid, E_USER_NOTICE);
 657         return true;
 658     }
 659
 660     public function dismiss_ufo($handle, $disconnect = true, $message = null) {
 661         if (empty($this->conn_ufo)) {
 662             return false;
 663         }
 664         foreach ($this->conn_ufo as $id => $ufo) {
 665             if ($ufo->handle == $handle) {
 666                 unset($this->conn_ufo[$id]);
 667                 if ($disconnect) {
 668                     if (!empty($message)) {
 669                         $this->write_data($handle, $message."\n\n");
 670                     }
 671                     socket_shutdown($handle);
 672                     socket_close($handle);
 673                 }
 674                 return true;
 675             }
 676         }
 677         return false;
 678     }
 679
 680     public function conn_accept() {
 681         $readsocket = array($this->listen_socket);
 682         $write = null;
 683         $except = null;
 684         $changed = socket_select($readsocket, $write, $except, 0, 0);
 685
 686         if (!$changed) {
 687             return false;
 688         }
 689         $handle = socket_accept($this->listen_socket);
 690         if (!$handle) {
 691             return false;
 692         }
 693
 694         $newconn = new ChatConnection($handle);
 695         $id = $this->new_ufo_id();
 696         $this->conn_ufo[$id] = $newconn;
 697     }
 698
 699     public function conn_activity_ufo(&$handles) {
 700         $monitor = array();
 701         if (!empty($this->conn_ufo)) {
 702             foreach ($this->conn_ufo as $ufoid => $ufo) {
 703                 $monitor[$ufoid] = $ufo->handle;
 704             }
 705         }
 706
 707         if (empty($monitor)) {
 708             $handles = array();
 709             return 0;
 710         }
 711
 712         $a = null;
 713         $b = null;
 714         $retval = socket_select($monitor, $a, $b, null);
 715         $handles = $monitor;
 716
 717         return $retval;
 718     }
 719
 720     public function message_broadcast($message, $sender) {
 721
 722         if (empty($this->conn_sets)) {
 723             return true;
 724         }
 725
 726         $now = time();
 727
 728         // First of all, mark this chatroom as having had activity now.
 729         $this->chatrooms[$message->chatid]['lastactivity'] = $now;
 730
 731         foreach ($this->sets_info as $sessionid => $info) {
 732             // We need to get handles from users that are in the same chatroom, same group.
 733             if ($info['chatid'] == $message->chatid &&
 734               ($info['groupid'] == $message->groupid || $message->groupid == 0)) {
 735
 736                 // Simply give them the message.
 737                 $output = chat_format_message_manually($message, $info['courseid'], $sender, $info['user']);
 738                 $this->trace('Delivering message "'.$output->text.'" to '.$this->conn_sets[$sessionid][CHAT_CONNECTION_CHANNEL]);
 739
 740                 if ($output->beep) {
 741                     $this->write_data($this->conn_sets[$sessionid][CHAT_CONNECTION_CHANNEL],
 742                                       '<embed src="'.$this->_beepsoundsrc.'" autostart="true" hidden="true" />');
 743                 }
 744
 745                 if ($info['quirks'] & QUIRK_CHUNK_UPDATE) {
 746                     $output->html .= $GLOBALS['CHAT_DUMMY_DATA'];
 747                     $output->html .= $GLOBALS['CHAT_DUMMY_DATA'];
 748                     $output->html .= $GLOBALS['CHAT_DUMMY_DATA'];
 749                 }
 750
 751                 if (!$this->write_data($this->conn_sets[$sessionid][CHAT_CONNECTION_CHANNEL], $output->html)) {
 752                     $this->disconnect_session($sessionid);
 753                 }
 754             }
 755         }
 756     }
 757
 758     public function disconnect_session($sessionid) {
 759         global $DB;
 760
 761         $info = $this->sets_info[$sessionid];
 762
 763         $DB->delete_records('chat_users', array('sid' => $sessionid));
 764         $msg = new stdClass;
 765         $msg->chatid = $info['chatid'];
 766         $msg->userid = $info['userid'];
 767         $msg->groupid = $info['groupid'];
 768         $msg->system = 1;
 769         $msg->message = 'exit';
 770         $msg->timestamp = time();
 771
 772         $this->trace('User has disconnected, destroying uid '.$info['userid'].' with SID '.$sessionid, E_USER_WARNING);
 773         chat_send_chatmessage($info['chatuser'], $msg->message, true);
 774
 775         // IMPORTANT, kill him BEFORE broadcasting, otherwise we 'll get infinite recursion!
 776         $latesender = $info['user'];
 777         $this->dismiss_set($sessionid);
 778         $this->message_broadcast($msg, $latesender);
 779     }
 780
 781     public function fatal($message) {
 782         $message .= "\n";
 783         if ($this->_logfile) {
 784             $this->trace($message, E_USER_ERROR);
 785         }
 786         echo "FATAL ERROR:: $message\n";
 787         die();
 788     }
 789
 790     public function init_sockets() {
 791         global $CFG;
 792
 793         $this->trace('Setting up sockets');
 794
 795         if (false === ($this->listen_socket = socket_create(AF_INET, SOCK_STREAM, 0))) {
 796             // Failed to create socket.
 797             $lasterr = socket_last_error();
 798             $this->fatal('socket_create() failed: '. socket_strerror($lasterr).' ['.$lasterr.']');
 799         }
 800
 801         if (!socket_bind($this->listen_socket, $CFG->chat_serverip, $CFG->chat_serverport)) {
 802             // Failed to bind socket.
 803             $lasterr = socket_last_error();
 804             $this->fatal('socket_bind() failed: '. socket_strerror($lasterr).' ['.$lasterr.']');
 805         }
 806
 807         if (!socket_listen($this->listen_socket, $CFG->chat_servermax)) {
 808             // Failed to get socket to listen.
 809             $lasterr = socket_last_error();
 810             $this->fatal('socket_listen() failed: '. socket_strerror($lasterr).' ['.$lasterr.']');
 811         }
 812
 813         // Socket has been initialized and is ready.
 814         $this->trace('Socket opened on port '.$CFG->chat_serverport);
 815
 816         // What exactly does this do? http://www.unixguide.net/network/socketfaq/4.5.shtml is still not enlightening enough for me.
 817         socket_set_option($this->listen_socket, SOL_SOCKET, SO_REUSEADDR, 1);
 818         socket_set_nonblock($this->listen_socket);
 819     }
 820
 821     public function cli_switch($switch, $param = null) {
 822         switch($switch) { // LOL!
 823             case 'reset':
 824                 // Reset sockets.
 825                 $this->_resetsocket = true;
 826                 return false;
 827             case 'start':
 828                 // Start the daemon.
 829                 $this->_readytogo = true;
 830                 return false;
 831             break;
 832             case 'v':
 833                 // Verbose mode.
 834                 $this->_trace_level = E_ALL;
 835                 return false;
 836             break;
 837             case 'l':
 838                 // Use logfile.
 839                 if (!empty($param)) {
 840                     $this->_logfile_name = $param;
 841                 }
 842                 $this->_logfile = @fopen($this->_logfile_name, 'a+');
 843                 if ($this->_logfile == false) {
 844                     $this->fatal('Failed to open '.$this->_logfile_name.' for writing');
 845                 }
 846                 return false;
 847             default:
 848                 // Unrecognized.
 849                 $this->fatal('Unrecognized command line switch: '.$switch);
 850             break;
 851         }
 852         return false;
 853     }
 854
 855 }
 856
 857 $daemon = new ChatDaemon;
 858 set_error_handler(array($daemon, 'error_handler'));
 859
 860 // Check the parameters.
 861
 862 unset($argv[0]);
 863 $commandline = implode(' ', $argv);
 864 if (strpos($commandline, '-') === false) {
 865     if (!empty($commandline)) {
 866         // We cannot have received any meaningful parameters.
 867         $daemon->fatal('Garbage in command line');
 868     }
 869 } else {
 870     // Parse command line.
 871     $switches = preg_split('/(-{1,2}[a-zA-Z]+) */', $commandline, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
 872
 873     // Taking advantage of the fact that $switches is indexed with incrementing numeric keys.
 874     // We will be using that to pass additional information to those switches who need it.
 875     $numswitches = count($switches);
 876
 877     // Fancy way to give a "hyphen" boolean flag to each "switch".
 878     $switches = array_map(create_function('$x', 'return array("str" => $x, "hyphen" => (substr($x, 0, 1) == "-"));'), $switches);
 879
 880     for ($i = 0; $i < $numswitches; ++$i) {
 881
 882         $switch = $switches[$i]['str'];
 883         $params = ($i == $numswitches - 1 ? null :
 884                                             ($switches[$i + 1]['hyphen'] ? null : trim($switches[$i + 1]['str']))
 885                   );
 886
 887         if (substr($switch, 0, 2) == '--') {
 888             // Double-hyphen switch.
 889             $daemon->cli_switch(strtolower(substr($switch, 2)), $params);
 890         } else if (substr($switch, 0, 1) == '-') {
 891             // Single-hyphen switch(es), may be more than one run together.
 892             $switch = substr($switch, 1); // Get rid of the "-".
 893             $len = strlen($switch);
 894             for ($j = 0; $j < $len; ++$j) {
 895                 $daemon->cli_switch(strtolower(substr($switch, $j, 1)), $params);
 896             }
 897         }
 898     }
 899 }
 900
 901 if (!$daemon->query_start()) {
 902     // For some reason we didn't start, so print out some info.
 903     echo 'Starts the Moodle chat socket server on port '.$CFG->chat_serverport;
 904     echo "\n\n";
 905     echo "Usage: chatd.php [parameters]\n\n";
 906     echo "Parameters:\n";
 907     echo "  --start         Starts the daemon\n";
 908     echo "  -v              Verbose mode (prints trivial information messages)\n";
 909     echo "  -l [logfile]    Log all messages to logfile (if not specified, chatd.log)\n";
 910     echo "Example:\n";
 911     echo "  chatd.php --start -l\n\n";
 912     die();
 913 }
 914
 915 if (!function_exists('socket_set_option')) {
 916     echo "Error: Function socket_set_option() does not exist.\n";
 917     echo "Possibly PHP has not been compiled with --enable-sockets.\n\n";
 918     die();
 919 }
 920
 921 $daemon->init_sockets();
 922
 923 $daemon->trace('Started Moodle chatd on port '.$CFG->chat_serverport.', listening socket '.$daemon->listen_socket, E_USER_WARNING);
 924
 925 // Clear the decks of old stuff.
 926 $DB->delete_records('chat_users', array('version' => 'sockets'));
 927
 928 while (true) {
 929     $active = array();
 930
 931     // First of all, let's see if any of our UFOs have identified itself.
 932     if ($daemon->conn_activity_ufo($active)) {
 933         foreach ($active as $handle) {
 934             $readsocket = array($handle);
 935             $write = null;
 936             $except = null;
 937             $changed = socket_select($readsocket, $write, $except, 0, 0);
 938
 939             if ($changed > 0) {
 940                 // Let's see what it has to say.
 941
 942                 $data = socket_read($handle, 2048); // Should be more than 512 to prevent empty pages and repeated messages!
 943                 if (empty($data)) {
 944                     continue;
 945                 }
 946
 947                 if (strlen($data) == 2048) { // If socket_read has more data, ignore all data.
 948                     $daemon->trace('UFO with '.$handle.': Data too long; connection closed', E_USER_WARNING);
 949                     $daemon->dismiss_ufo($handle, true, 'Data too long; connection closed');
 950                     continue;
 951                 }
 952
 953                 if (!preg_match('/win=(chat|users|message|beep).*&chat_sid=([a-zA-Z0-9]*) HTTP/', $data, $info)) {
 954                     // Malformed data.
 955                     $daemon->trace('UFO with '.$handle.': Request with malformed data; connection closed', E_USER_WARNING);
 956                     $daemon->dismiss_ufo($handle, true, 'Request with malformed data; connection closed');
 957                     continue;
 958                 }
 959
 960                 $type      = $info[1];
 961                 $sessionid = $info[2];
 962
 963                 $customdata = array();
 964
 965                 switch($type) {
 966                     case 'chat':
 967                         $type = CHAT_CONNECTION_CHANNEL;
 968                         $customdata['quirks'] = 0;
 969                         if (strpos($data, 'Safari')) {
 970                             $daemon->trace('Safari identified...', E_USER_WARNING);
 971                             $customdata['quirks'] += QUIRK_CHUNK_UPDATE;
 972                         }
 973                     break;
 974                     case 'users':
 975                         $type = CHAT_SIDEKICK_USERS;
 976                     break;
 977                     case 'beep':
 978                         $type = CHAT_SIDEKICK_BEEP;
 979                         if (!preg_match('/beep=([^&]*)[& ]/', $data, $info)) {
 980                             $daemon->trace('Beep sidekick did not contain a valid userid', E_USER_WARNING);
 981                             $daemon->dismiss_ufo($handle, true, 'Request with malformed data; connection closed');
 982                             continue;
 983                         } else {
 984                             $customdata = array('beep' => intval($info[1]));
 985                         }
 986                     break;
 987                     case 'message':
 988                         $type = CHAT_SIDEKICK_MESSAGE;
 989                         if (!preg_match('/chat_message=([^&]*)[& ]chat_msgidnr=([^&]*)[& ]/', $data, $info)) {
 990                             $daemon->trace('Message sidekick did not contain a valid message', E_USER_WARNING);
 991                             $daemon->dismiss_ufo($handle, true, 'Request with malformed data; connection closed');
 992                             continue;
 993                         } else {
 994                             $customdata = array('message' => $info[1], 'index' => $info[2]);
 995                         }
 996                     break;
 997                     default:
 998                         $daemon->trace('UFO with '.$handle.': Request with unknown type; connection closed', E_USER_WARNING);
 999                         $daemon->dismiss_ufo($handle, true, 'Request with unknown type; connection closed');
1000                         continue;
1001                     break;
1002                 }
1003
1004                 // OK, now we know it's something good. Promote it and pass it all the data it needs.
1005                 $daemon->promote_ufo($handle, $type, $sessionid, $customdata);
1006                 continue;
1007             }
1008         }
1009     }
1010
1011     $now = time();
1012
1013     // Clean up chatrooms with no activity as required.
1014     if ($now - $daemon->_last_idle_poll >= $daemon->_freq_poll_idle_chat) {
1015         $daemon->poll_idle_chats($now);
1016     }
1017
1018     // Finally, accept new connections.
1019     $daemon->conn_accept();
1020
1021     usleep($daemon->_time_rest_socket);
1022 }
1023
1024 @socket_shutdown($daemon->listen_socket, 0);
1025 die("\n\n-- terminated --\n");
1026