MDL-31500 backup: Warn users about front page backups
[moodle.git] / 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/>.
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  */
25 define('CLI_SCRIPT', true);
27 require(dirname(dirname(dirname(__FILE__))).'/config.php');
28 require_once($CFG->dirroot . '/mod/chat/lib.php');
30 // Browser quirks.
31 define('QUIRK_CHUNK_UPDATE', 0x0001);
33 // Connection telltale.
34 define('CHAT_CONNECTION',           0x10);
35 // Connections: Incrementing sequence, 0x10 to 0x1f.
36 define('CHAT_CONNECTION_CHANNEL',   0x11);
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);
45 $phpversion = phpversion();
46 echo 'Moodle chat daemon v1.0 on PHP '.$phpversion."\n\n";
48 // Set up all the variables we need.
50 // The $CFG variables are now defined in database by chat/lib.php.
52 $_SERVER['PHP_SELF']        = 'dummy';
53 $_SERVER['SERVER_NAME']     = 'dummy';
54 $_SERVER['HTTP_USER_AGENT'] = 'dummy';
56 $_SERVER['SERVER_NAME'] = $CFG->chat_serverhost;
57 $_SERVER['PHP_SELF']    = "http://$CFG->chat_serverhost:$CFG->chat_serverport/mod/chat/chatd.php";
59 core_php_time_limit::raise(0);
60 error_reporting(E_ALL);
62 function chat_empty_connection() {
63     return array('sid' => null, 'handle' => null, 'ip' => null, 'port' => null, 'groupid' => null);
64 }
66 class ChatConnection {
67     // Chat-related info.
68     public $sid  = null;
69     public $type = null;
71     // PHP-level info.
72     public $handle = null;
74     // TCP/IP.
75     public $ip     = null;
76     public $port   = null;
78     public function __construct($resource) {
79         $this->handle = $resource;
80         @socket_getpeername($this->handle, $this->ip, $this->port);
81     }
82 }
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;
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.
100     // IMPORTANT: $connectionssets, $setsinfo and $chatrooms must remain synchronized!
101     //            Pay extra attention when you write code that affects any of them!
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             $this->_trace_to_console = false;
114         }
115     }
117     public function error_handler ($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, $errno);
121         }
122         return true;
123     }
125     public function poll_idle_chats($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     }
149     public function query_start() {
150         return $this->_readytogo;
151     }
153     public function trace($message, $level = E_USER_NOTICE) {
154         $severity = '';
156         switch($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         }
169         $date = date('[Y-m-d H:i:s] ');
170         $message = $date.$severity.$message."\n";
172         if ($this->_trace_level & $level) {
173             // It is accepted for output.
175             // Error-class traces go to STDERR too.
176             if ($level & E_USER_ERROR) {
177                 fwrite(STDERR, $message);
178             }
180             // Emit the message to wherever we should.
181             if ($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     }
196     public function write_data($connection, $text) {
197         $written = @socket_write($connection, $text, strlen($text));
198         if ($written === false) {
199             return false;
200         }
201         return true;
202     }
204     public function user_lazy_update($sessionid) {
205         global $DB;
207         if (empty($this->sets_info[$sessionid])) {
208             $this->trace('user_lazy_update() called for an invalid SID: '.$sessionid, E_USER_WARNING);
209             return false;
210         }
212         $now = time();
214         // We 'll be cheating a little, and NOT updating the record data as
215         // often as we can, so that we save on DB queries (imagine MANY users).
216         if ($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     }
224     public function get_user_window($sessionid) {
225         global $CFG, $OUTPUT;
227         static $str;
229         $info = &$this->sets_info[$sessionid];
231         $timenow = time();
233         if (empty($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         }
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;
269         // Get the users from that chatroom.
270         $users = $this->chatrooms[$info['chatid']]['users'];
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];
276             $lastping = $timenow - $userinfo['chatuser']->lastmessageping;
278             echo '<tr><td width="35">';
280             $link = '/user/view.php?id='.$userinfo['user']->id.'&course='.$userinfo['courseid'];
281             $anchortagcontents = $OUTPUT->user_picture($userinfo['user'], array('courseid' => $userinfo['courseid']));
283             $action = new popup_action('click', $link, 'user'.$userinfo['chatuser']->id);
284             $anchortag = $OUTPUT->action_link($link, $anchortagcontents, $action);
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         }
298         echo '</tbody></table>';
299         echo "</body>\n</html>\n";
301         return ob_get_clean();
303     }
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 $id;
311     }
313     public function process_sidekicks($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     }
325     public function dispatch_sidekick($handle, $type, $sessionid, $customdata) {
326         global $CFG, $DB;
328         switch($type) {
329             case CHAT_SIDEKICK_BEEP:
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                 $msg->timestamp = time();
340                 // Commit to DB.
341                 chat_send_chatmessage($this->sets_info[$sessionid]['chatuser'], $msg->message, false,
342                     $this->sets_info[$sessionid]['cm']);
344                 // OK, now push it out to all users.
345                 $this->message_broadcast($msg, $this->sets_info[$sessionid]['user']);
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);
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.
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";
366                 // That's enough headers for one lousy dummy response.
367                 $this->write_data($handle, $header);
368                 // All done.
369             break;
371             case CHAT_SIDEKICK_USERS:
372                 // A request to paint a user window.
374                 $content = $this->get_user_window($sessionid);
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";
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";
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);
398                 // Update that user's lastping.
399                 $this->sets_info[$sessionid]['chatuser']->lastping = time();
400                 $this->user_lazy_update($sessionid);
402             break;
404             case CHAT_SIDEKICK_MESSAGE:
405                 // Incoming message.
407                 // Browser stupidity protection from duplicate messages.
408                 $messageindex = intval($customdata['index']);
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                 }
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                 $msg->timestamp = time();
426                 if (empty($msg->message)) {
427                     // Someone just hit ENTER, send them on their way.
428                     break;
429                 }
431                 // A slight hack to prevent malformed SQL inserts.
432                 $origmsg = $msg->message;
433                 $msg->message = $msg->message;
435                 // Commit to DB.
436                 chat_send_chatmessage($this->sets_info[$sessionid]['chatuser'], $msg->message, false,
437                     $this->sets_info[$sessionid]['cm']);
439                 // Undo the hack.
440                 $msg->message = $origmsg;
442                 // OK, now push it out to all users.
443                 $this->message_broadcast($msg, $this->sets_info[$sessionid]['user']);
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);
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.
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";
464                 // That's enough headers for one lousy dummy response.
465                 $this->write_data($handle, $header);
467                 // All done.
468             break;
469         }
471         socket_shutdown($handle);
472         socket_close($handle);
473     }
475     public function promote_final($sessionid, $customdata) {
476         global $DB;
478         if (isset($this->conn_sets[$sessionid])) {
479             $this->trace('Set cannot be finalized: Session '.$sessionid.' is already active');
480             return false;
481         }
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         }
508         global $CHAT_HTMLHEAD_JS;
510         $this->conn_sets[$sessionid] = $this->conn_half[$sessionid];
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'    => $customdata['quirks']
527         );
529         // If we know nothing about this chatroom, initialize it and add the user.
530         if (!isset($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         }
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";
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);
558         // Finally, broadcast the "entered the chat" message.
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         $msg->timestamp = time();
568         chat_send_chatmessage($chatuser, $msg->message, true);
569         $this->message_broadcast($msg, $this->sets_info[$sessionid]['user']);
571         return true;
572     }
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 == $handle) {
580                 // OK, got the id of the UFO, but what is it?
582                 if ($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' => $customdata);
592                     }
593                     return true;
594                 }
596                 // If it's not a sidekick, at this point it can only be da man.
598                 if ($type & CHAT_CONNECTION) {
599                     // This forces a new connection right now.
600                     $this->trace('Incoming connection from '.$ufo->ip.':'.$ufo->port);
602                     // Do we have such a connection active?
603                     if (isset($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                     }
610                     // Join this with what we may have already.
611                     $this->conn_half[$sessionid][$type] = $handle;
613                     // Do the bookkeeping.
614                     $this->promote_final($sessionid, $customdata);
616                     // It's not a UFO anymore.
617                     $this->dismiss_ufo($handle, false);
619                     // Dispatch waiting sidekicks.
620                     $this->process_sidekicks($sessionid);
622                     return true;
623                 }
624             }
625         }
626         return false;
627     }
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[$sessionid]);
640         return true;
641     }
643     public function dismiss_set($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     }
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     }
680     public function conn_accept() {
681         $readsocket = array($this->listen_socket);
682         $write = null;
683         $except = null;
684         $changed = socket_select($readsocket, $write, $except, 0, 0);
686         if (!$changed) {
687             return false;
688         }
689         $handle = socket_accept($this->listen_socket);
690         if (!$handle) {
691             return false;
692         }
694         $newconn = new ChatConnection($handle);
695         $id = $this->new_ufo_id();
696         $this->conn_ufo[$id] = $newconn;
697     }
699     public function conn_activity_ufo(&$handles) {
700         $monitor = array();
701         if (!empty($this->conn_ufo)) {
702             foreach ($this->conn_ufo as $ufoid => $ufo) {
703                 $monitor[$ufoid] = $ufo->handle;
704             }
705         }
707         if (empty($monitor)) {
708             $handles = array();
709             return 0;
710         }
712         $a = null;
713         $b = null;
714         $retval = socket_select($monitor, $a, $b, null);
715         $handles = $monitor;
717         return $retval;
718     }
720     public function message_broadcast($message, $sender) {
722         if (empty($this->conn_sets)) {
723             return true;
724         }
726         $now = time();
728         // First of all, mark this chatroom as having had activity now.
729         $this->chatrooms[$message->chatid]['lastactivity'] = $now;
731         foreach ($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)) {
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]);
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                 }
745                 if ($info['quirks'] & QUIRK_CHUNK_UPDATE) {
746                     $output->html .= $GLOBALS['CHAT_DUMMY_DATA'];
747                     $output->html .= $GLOBALS['CHAT_DUMMY_DATA'];
748                     $output->html .= $GLOBALS['CHAT_DUMMY_DATA'];
749                 }
751                 if (!$this->write_data($this->conn_sets[$sessionid][CHAT_CONNECTION_CHANNEL], $output->html)) {
752                     $this->disconnect_session($sessionid);
753                 }
754             }
755         }
756     }
758     public function disconnect_session($sessionid) {
759         global $DB;
761         $info = $this->sets_info[$sessionid];
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();
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);
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, $latesender);
779     }
781     public function fatal($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     }
790     public function init_sockets() {
791         global $CFG;
793         $this->trace('Setting up sockets');
795         if (false === ($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).' ['.$lasterr.']');
799         }
801         if (!socket_bind($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).' ['.$lasterr.']');
805         }
807         if (!socket_listen($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         }
813         // Socket has been initialized and is ready.
814         $this->trace('Socket opened on port '.$CFG->chat_serverport);
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     }
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     }
857 $daemon = new ChatDaemon;
858 set_error_handler(array($daemon, 'error_handler'));
860 // Check the parameters.
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);
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);
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) == "-"));'), $switches);
880     for ($i = 0; $i < $numswitches; ++$i) {
882         $switch = $switches[$i]['str'];
883         $params = ($i == $numswitches - 1 ? null :
884                                             ($switches[$i + 1]['hyphen'] ? null : trim($switches[$i + 1]['str']))
885                   );
887         if (substr($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)), $params);
896             }
897         }
898     }
901 if (!$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();
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();
921 $daemon->init_sockets();
923 $daemon->trace('Started Moodle chatd on port '.$CFG->chat_serverport.', listening socket '.$daemon->listen_socket, E_USER_WARNING);
925 // Clear the decks of old stuff.
926 $DB->delete_records('chat_users', array('version' => 'sockets'));
928 while (true) {
929     $active = array();
931     // First of all, let's see if any of our UFOs have identified itself.
932     if ($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, $except, 0, 0);
939             if ($changed > 0) {
940                 // Let's see what it has to say.
942                 $data = socket_read($handle, 2048); // Should be more than 512 to prevent empty pages and repeated messages!
943                 if (empty($data)) {
944                     continue;
945                 }
947                 if (strlen($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                 }
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                 }
960                 $type      = $info[1];
961                 $sessionid = $info[2];
963                 $customdata = array();
965                 switch($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                 }
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     }
1011     $now = time();
1013     // Clean up chatrooms with no activity as required.
1014     if ($now - $daemon->_last_idle_poll >= $daemon->_freq_poll_idle_chat) {
1015         $daemon->poll_idle_chats($now);
1016     }
1018     // Finally, accept new connections.
1019     $daemon->conn_accept();
1021     usleep($daemon->_time_rest_socket);
1024 @socket_shutdown($daemon->listen_socket, 0);
1025 die("\n\n-- terminated --\n");