bootstrap.inc 114 KB
Newer Older
1
<?php
2

3 4 5 6
/**
 * @file
 * Functions that need to be loaded on every Drupal request.
 */
7

8 9 10
/**
 * The current system version.
 */
David_Rothstein's avatar
David_Rothstein committed
11
define('VERSION', '7.23-dev');
12 13 14 15 16 17 18 19 20

/**
 * Core API compatibility.
 */
define('DRUPAL_CORE_COMPATIBILITY', '7.x');

/**
 * Minimum supported version of PHP.
 */
21
define('DRUPAL_MINIMUM_PHP', '5.2.4');
22 23 24 25

/**
 * Minimum recommended value of PHP memory_limit.
 */
26
define('DRUPAL_MINIMUM_PHP_MEMORY_LIMIT', '32M');
27

28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
/**
 * Error reporting level: display no errors.
 */
define('ERROR_REPORTING_HIDE', 0);

/**
 * Error reporting level: display errors and warnings.
 */
define('ERROR_REPORTING_DISPLAY_SOME', 1);

/**
 * Error reporting level: display all messages.
 */
define('ERROR_REPORTING_DISPLAY_ALL', 2);

43
/**
44 45 46
 * Indicates that the item should never be removed unless explicitly selected.
 *
 * The item may be removed using cache_clear_all() with a cache ID.
47
 */
48
define('CACHE_PERMANENT', 0);
49 50 51 52

/**
 * Indicates that the item should be removed at the next general cache wipe.
 */
53
define('CACHE_TEMPORARY', -1);
54

55
/**
56 57 58
 * @defgroup logging_severity_levels Logging severity levels
 * @{
 * Logging severity levels as defined in RFC 3164.
59
 *
60
 * The WATCHDOG_* constant definitions correspond to the logging severity levels
61
 * defined in RFC 3164, section 4.1.1. PHP supplies predefined LOG_* constants
62
 * for use in the syslog() function, but their values on Windows builds do not
63
 * correspond to RFC 3164. The associated PHP bug report was closed with the
64 65 66 67 68 69 70
 * comment, "And it's also not a bug, as Windows just have less log levels,"
 * and "So the behavior you're seeing is perfectly normal."
 *
 * @see http://www.faqs.org/rfcs/rfc3164.html
 * @see http://bugs.php.net/bug.php?id=18090
 * @see http://php.net/manual/function.syslog.php
 * @see http://php.net/manual/network.constants.php
71 72
 * @see watchdog()
 * @see watchdog_severity_levels()
73
 */
74 75 76 77

/**
 * Log message severity -- Emergency: system is unusable.
 */
78
define('WATCHDOG_EMERGENCY', 0);
79 80 81 82 83 84 85

/**
 * Log message severity -- Alert: action must be taken immediately.
 */
define('WATCHDOG_ALERT', 1);

/**
86
 * Log message severity -- Critical conditions.
87 88 89 90
 */
define('WATCHDOG_CRITICAL', 2);

/**
91
 * Log message severity -- Error conditions.
92 93 94 95
 */
define('WATCHDOG_ERROR', 3);

/**
96
 * Log message severity -- Warning conditions.
97 98 99 100
 */
define('WATCHDOG_WARNING', 4);

/**
101
 * Log message severity -- Normal but significant conditions.
102 103 104 105
 */
define('WATCHDOG_NOTICE', 5);

/**
106
 * Log message severity -- Informational messages.
107 108 109 110
 */
define('WATCHDOG_INFO', 6);

/**
111
 * Log message severity -- Debug-level messages.
112 113
 */
define('WATCHDOG_DEBUG', 7);
114

115 116 117 118
/**
 * @} End of "defgroup logging_severity_levels".
 */

119 120 121
/**
 * First bootstrap phase: initialize configuration.
 */
122
define('DRUPAL_BOOTSTRAP_CONFIGURATION', 0);
123 124

/**
125
 * Second bootstrap phase: try to serve a cached page.
126
 */
127
define('DRUPAL_BOOTSTRAP_PAGE_CACHE', 1);
128 129 130 131

/**
 * Third bootstrap phase: initialize database layer.
 */
132
define('DRUPAL_BOOTSTRAP_DATABASE', 2);
133 134

/**
135
 * Fourth bootstrap phase: initialize the variable system.
136
 */
137
define('DRUPAL_BOOTSTRAP_VARIABLES', 3);
138 139

/**
140
 * Fifth bootstrap phase: initialize session handling.
141
 */
142
define('DRUPAL_BOOTSTRAP_SESSION', 4);
143 144

/**
145
 * Sixth bootstrap phase: set up the page header.
146
 */
147
define('DRUPAL_BOOTSTRAP_PAGE_HEADER', 5);
148 149

/**
150
 * Seventh bootstrap phase: find out language of the page.
151
 */
152
define('DRUPAL_BOOTSTRAP_LANGUAGE', 6);
153 154

/**
155
 * Final bootstrap phase: Drupal is fully loaded; validate and fix input data.
156
 */
157
define('DRUPAL_BOOTSTRAP_FULL', 7);
158

159 160 161
/**
 * Role ID for anonymous users; should match what's in the "role" table.
 */
162
define('DRUPAL_ANONYMOUS_RID', 1);
163 164 165 166

/**
 * Role ID for authenticated users; should match what's in the "role" table.
 */
167 168
define('DRUPAL_AUTHENTICATED_RID', 2);

169
/**
170 171 172
 * The number of bytes in a kilobyte.
 *
 * For more information, visit http://en.wikipedia.org/wiki/Kilobyte.
173 174 175
 */
define('DRUPAL_KILOBYTE', 1024);

176 177 178
/**
 * The language code used when no language is explicitly assigned.
 *
179
 * Defined by ISO639-2 for "Undetermined".
180
 */
181
define('LANGUAGE_NONE', 'und');
182

183
/**
184
 * The type of language used to define the content language.
185
 */
186
define('LANGUAGE_TYPE_CONTENT', 'language_content');
187 188

/**
189
 * The type of language used to select the user interface.
190
 */
191
define('LANGUAGE_TYPE_INTERFACE', 'language');
192 193

/**
194
 * The type of language used for URLs.
195
 */
196
define('LANGUAGE_TYPE_URL', 'language_url');
197

198 199 200 201 202 203 204 205 206 207
/**
 * Language written left to right. Possible value of $language->direction.
 */
define('LANGUAGE_LTR', 0);

/**
 * Language written right to left. Possible value of $language->direction.
 */
define('LANGUAGE_RTL', 1);

208
/**
209
 * Time of the current request in seconds elapsed since the Unix Epoch.
210
 *
211 212 213 214 215 216
 * This differs from $_SERVER['REQUEST_TIME'], which is stored as a float
 * since PHP 5.4.0. Float timestamps confuse most PHP functions
 * (including date_create()).
 *
 * @see http://php.net/manual/reserved.variables.server.php
 * @see http://php.net/manual/function.time.php
217
 */
218
define('REQUEST_TIME', (int) $_SERVER['REQUEST_TIME']);
219

220 221 222 223 224 225 226 227 228 229
/**
 * Flag for drupal_set_title(); text is not sanitized, so run check_plain().
 */
define('CHECK_PLAIN', 0);

/**
 * Flag for drupal_set_title(); text has already been sanitized.
 */
define('PASS_THROUGH', -1);

230
/**
231
 * Signals that the registry lookup cache should be reset.
232 233 234 235
 */
define('REGISTRY_RESET_LOOKUP_CACHE', 1);

/**
236
 * Signals that the registry lookup cache should be written to storage.
237 238 239
 */
define('REGISTRY_WRITE_LOOKUP_CACHE', 2);

240 241 242 243 244 245 246
/**
 * Regular expression to match PHP function names.
 *
 * @see http://php.net/manual/en/language.functions.php
 */
define('DRUPAL_PHP_FUNCTION_PATTERN', '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*');

247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296
/**
 * Provides a caching wrapper to be used in place of large array structures.
 *
 * This class should be extended by systems that need to cache large amounts
 * of data and have it represented as an array to calling functions. These
 * arrays can become very large, so ArrayAccess is used to allow different
 * strategies to be used for caching internally (lazy loading, building caches
 * over time etc.). This can dramatically reduce the amount of data that needs
 * to be loaded from cache backends on each request, and memory usage from
 * static caches of that same data.
 *
 * Note that array_* functions do not work with ArrayAccess. Systems using
 * DrupalCacheArray should use this only internally. If providing API functions
 * that return the full array, this can be cached separately or returned
 * directly. However since DrupalCacheArray holds partial content by design, it
 * should be a normal PHP array or otherwise contain the full structure.
 *
 * Note also that due to limitations in PHP prior to 5.3.4, it is impossible to
 * write directly to the contents of nested arrays contained in this object.
 * Only writes to the top-level array elements are possible. So if you
 * previously had set $object['foo'] = array(1, 2, 'bar' => 'baz'), but later
 * want to change the value of 'bar' from 'baz' to 'foobar', you cannot do so
 * a targeted write like $object['foo']['bar'] = 'foobar'. Instead, you must
 * overwrite the entire top-level 'foo' array with the entire set of new
 * values: $object['foo'] = array(1, 2, 'bar' => 'foobar'). Due to this same
 * limitation, attempts to create references to any contained data, nested or
 * otherwise, will fail silently. So $var = &$object['foo'] will not throw an
 * error, and $var will be populated with the contents of $object['foo'], but
 * that data will be passed by value, not reference. For more information on
 * the PHP limitation, see the note in the official PHP documentation at·
 * http://php.net/manual/en/arrayaccess.offsetget.php on
 * ArrayAccess::offsetGet().
 *
 * By default, the class accounts for caches where calling functions might
 * request keys in the array that won't exist even after a cache rebuild. This
 * prevents situations where a cache rebuild would be triggered over and over
 * due to a 'missing' item. These cases are stored internally as a value of
 * NULL. This means that the offsetGet() and offsetExists() methods
 * must be overridden if caching an array where the top level values can
 * legitimately be NULL, and where $object->offsetExists() needs to correctly
 * return (equivalent to array_key_exists() vs. isset()). This should not
 * be necessary in the majority of cases.
 *
 * Classes extending this class must override at least the
 * resolveCacheMiss() method to have a working implementation.
 *
 * offsetSet() is not overridden by this class by default. In practice this
 * means that assigning an offset via arrayAccess will only apply while the
 * object is in scope and will not be written back to the persistent cache.
 * This follows a similar pattern to static vs. persistent caching in
297
 * procedural code. Extending classes may wish to alter this behavior, for
298 299 300 301 302 303 304 305 306
 * example by overriding offsetSet() and adding an automatic call to persist().
 *
 * @see SchemaCache
 */
abstract class DrupalCacheArray implements ArrayAccess {

  /**
   * A cid to pass to cache_set() and cache_get().
   */
307
  protected $cid;
308 309 310 311

  /**
   * A bin to pass to cache_set() and cache_get().
   */
312
  protected $bin;
313 314 315 316 317 318 319 320 321 322 323 324

  /**
   * An array of keys to add to the cache at the end of the request.
   */
  protected $keysToPersist = array();

  /**
   * Storage for the data itself.
   */
  protected $storage = array();

  /**
325
   * Constructs a DrupalCacheArray object.
326 327 328 329 330 331 332 333 334 335 336 337 338 339 340
   *
   * @param $cid
   *   The cid for the array being cached.
   * @param $bin
   *   The bin to cache the array.
   */
  public function __construct($cid, $bin) {
    $this->cid = $cid;
    $this->bin = $bin;

    if ($cached = cache_get($this->cid, $this->bin)) {
     $this->storage = $cached->data;
    }
  }

341 342 343
  /**
   * Implements ArrayAccess::offsetExists().
   */
344 345 346 347
  public function offsetExists($offset) {
    return $this->offsetGet($offset) !== NULL;
  }

348 349 350
  /**
   * Implements ArrayAccess::offsetGet().
   */
351 352 353 354 355 356 357 358 359
  public function offsetGet($offset) {
    if (isset($this->storage[$offset]) || array_key_exists($offset, $this->storage)) {
      return $this->storage[$offset];
    }
    else {
      return $this->resolveCacheMiss($offset);
    }
  }

360 361 362
  /**
   * Implements ArrayAccess::offsetSet().
   */
363 364 365 366
  public function offsetSet($offset, $value) {
    $this->storage[$offset] = $value;
  }

367 368 369
  /**
   * Implements ArrayAccess::offsetUnset().
   */
370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408
  public function offsetUnset($offset) {
    unset($this->storage[$offset]);
  }

  /**
   * Flags an offset value to be written to the persistent cache.
   *
   * If a value is assigned to a cache object with offsetSet(), by default it
   * will not be written to the persistent cache unless it is flagged with this
   * method. This allows items to be cached for the duration of a request,
   * without necessarily writing back to the persistent cache at the end.
   *
   * @param $offset
   *   The array offset that was request.
   * @param $persist
   *   Optional boolean to specify whether the offset should be persisted or
   *   not, defaults to TRUE. When called with $persist = FALSE the offset will
   *   be unflagged so that it will not written at the end of the request.
   */
  protected function persist($offset, $persist = TRUE) {
    $this->keysToPersist[$offset] = $persist;
  }

  /**
   * Resolves a cache miss.
   *
   * When an offset is not found in the object, this is treated as a cache
   * miss. This method allows classes implementing the interface to look up
   * the actual value and allow it to be cached.
   *
   * @param $offset
   *   The offset that was requested.
   *
   * @return
   *   The value of the offset, or NULL if no value was found.
   */
  abstract protected function resolveCacheMiss($offset);

  /**
409
   * Writes a value to the persistent cache immediately.
410 411 412 413 414 415
   *
   * @param $data
   *   The data to write to the persistent cache.
   * @param $lock
   *   Whether to acquire a lock before writing to cache.
   */
416
  protected function set($data, $lock = TRUE) {
417 418
    // Lock cache writes to help avoid stampedes.
    // To implement locking for cache misses, override __construct().
419
    $lock_name = $this->cid . ':' . $this->bin;
420
    if (!$lock || lock_acquire($lock_name)) {
421
      if ($cached = cache_get($this->cid, $this->bin)) {
422 423
        $data = $cached->data + $data;
      }
424
      cache_set($this->cid, $data, $this->bin);
425 426 427 428 429 430
      if ($lock) {
        lock_release($lock_name);
      }
    }
  }

431 432 433
  /**
   * Destructs the DrupalCacheArray object.
   */
434 435 436 437 438 439 440 441
  public function __destruct() {
    $data = array();
    foreach ($this->keysToPersist as $offset => $persist) {
      if ($persist) {
        $data[$offset] = $this->storage[$offset];
      }
    }
    if (!empty($data)) {
442
      $this->set($data);
443 444 445 446
    }
  }
}

447
/**
448 449 450 451
 * Starts the timer with the specified name.
 *
 * If you start and stop the same timer multiple times, the measured intervals
 * will be accumulated.
452
 *
453
 * @param $name
454 455 456 457 458
 *   The name of the timer.
 */
function timer_start($name) {
  global $timers;

459
  $timers[$name]['start'] = microtime(TRUE);
460
  $timers[$name]['count'] = isset($timers[$name]['count']) ? ++$timers[$name]['count'] : 1;
461 462 463
}

/**
464
 * Reads the current timer value without stopping the timer.
465
 *
466
 * @param $name
467
 *   The name of the timer.
468
 *
469 470 471 472 473 474
 * @return
 *   The current timer value in ms.
 */
function timer_read($name) {
  global $timers;

475
  if (isset($timers[$name]['start'])) {
476
    $stop = microtime(TRUE);
477
    $diff = round(($stop - $timers[$name]['start']) * 1000, 2);
478

479 480 481 482
    if (isset($timers[$name]['time'])) {
      $diff += $timers[$name]['time'];
    }
    return $diff;
483
  }
484
  return $timers[$name]['time'];
485 486 487
}

/**
488
 * Stops the timer with the specified name.
489
 *
490
 * @param $name
491
 *   The name of the timer.
492
 *
493
 * @return
494 495
 *   A timer array. The array contains the number of times the timer has been
 *   started and stopped (count) and the accumulated timer value in ms (time).
496 497 498 499
 */
function timer_stop($name) {
  global $timers;

500 501 502 503 504 505 506 507 508 509
  if (isset($timers[$name]['start'])) {
    $stop = microtime(TRUE);
    $diff = round(($stop - $timers[$name]['start']) * 1000, 2);
    if (isset($timers[$name]['time'])) {
      $timers[$name]['time'] += $diff;
    }
    else {
      $timers[$name]['time'] = $diff;
    }
    unset($timers[$name]['start']);
510
  }
511 512 513

  return $timers[$name];
}
514

515
/**
516
 * Returns the appropriate configuration directory.
517
 *
518 519 520 521
 * Returns the configuration path based on the site's hostname, port, and
 * pathname. Uses find_conf_path() to find the current configuration directory.
 * See default.settings.php for examples on how the URL is converted to a
 * directory.
522
 *
523
 * @param bool $require_settings
524 525 526 527
 *   Only configuration directories with an existing settings.php file
 *   will be recognized. Defaults to TRUE. During initial installation,
 *   this is set to FALSE so that Drupal can detect a matching directory,
 *   then create a new settings.php file in it.
528
 * @param bool $reset
529
 *   Force a full search for matching directories even if one had been
530 531
 *   found previously. Defaults to FALSE.
 *
532 533
 * @return
 *   The path of the matching directory.
534 535
 *
 * @see default.settings.php
536
 */
537
function conf_path($require_settings = TRUE, $reset = FALSE) {
538
  $conf = &drupal_static(__FUNCTION__, '');
539

540
  if ($conf && !$reset) {
541 542
    return $conf;
  }
543

544
  $confdir = 'sites';
545 546 547 548 549 550 551

  $sites = array();
  if (file_exists(DRUPAL_ROOT . '/' . $confdir . '/sites.php')) {
    // This will overwrite $sites with the desired mappings.
    include(DRUPAL_ROOT . '/' . $confdir . '/sites.php');
  }

552
  $uri = explode('/', $_SERVER['SCRIPT_NAME'] ? $_SERVER['SCRIPT_NAME'] : $_SERVER['SCRIPT_FILENAME']);
553
  $server = explode('.', implode('.', array_reverse(explode(':', rtrim($_SERVER['HTTP_HOST'], '.')))));
554 555 556
  for ($i = count($uri) - 1; $i > 0; $i--) {
    for ($j = count($server); $j > 0; $j--) {
      $dir = implode('.', array_slice($server, -$j)) . implode('.', array_slice($uri, 0, $i));
557 558 559 560
      if (isset($sites[$dir]) && file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $sites[$dir])) {
        $dir = $sites[$dir];
      }
      if (file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $dir . '/settings.php') || (!$require_settings && file_exists(DRUPAL_ROOT . '/' . $confdir . '/' . $dir))) {
561 562 563
        $conf = "$confdir/$dir";
        return $conf;
      }
564 565
    }
  }
566 567
  $conf = "$confdir/default";
  return $conf;
568 569
}

570
/**
571
 * Sets appropriate server variables needed for command line scripts to work.
572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604
 *
 * This function can be called by command line scripts before bootstrapping
 * Drupal, to ensure that the page loads with the desired server parameters.
 * This is because many parts of Drupal assume that they are running in a web
 * browser and therefore use information from the global PHP $_SERVER variable
 * that does not get set when Drupal is run from the command line.
 *
 * In many cases, the default way in which this function populates the $_SERVER
 * variable is sufficient, and it can therefore be called without passing in
 * any input. However, command line scripts running on a multisite installation
 * (or on any installation that has settings.php stored somewhere other than
 * the sites/default folder) need to pass in the URL of the site to allow
 * Drupal to detect the correct location of the settings.php file. Passing in
 * the 'url' parameter is also required for functions like request_uri() to
 * return the expected values.
 *
 * Most other parameters do not need to be passed in, but may be necessary in
 * some cases; for example, if Drupal's ip_address() function needs to return
 * anything but the standard localhost value ('127.0.0.1'), the command line
 * script should pass in the desired value via the 'REMOTE_ADDR' key.
 *
 * @param $variables
 *   (optional) An associative array of variables within $_SERVER that should
 *   be replaced. If the special element 'url' is provided in this array, it
 *   will be used to populate some of the server defaults; it should be set to
 *   the URL of the current page request, excluding any $_GET request but
 *   including the script name (e.g., http://www.example.com/mysite/index.php).
 *
 * @see conf_path()
 * @see request_uri()
 * @see ip_address()
 */
function drupal_override_server_variables($variables = array()) {
605
  // Allow the provided URL to override any existing values in $_SERVER.
606 607
  if (isset($variables['url'])) {
    $url = parse_url($variables['url']);
608 609 610 611 612 613
    if (isset($url['host'])) {
      $_SERVER['HTTP_HOST'] = $url['host'];
    }
    if (isset($url['path'])) {
      $_SERVER['SCRIPT_NAME'] = $url['path'];
    }
614 615
    unset($variables['url']);
  }
616 617 618
  // Define default values for $_SERVER keys. These will be used if $_SERVER
  // does not already define them and no other values are passed in to this
  // function.
619
  $defaults = array(
620 621
    'HTTP_HOST' => 'localhost',
    'SCRIPT_NAME' => NULL,
622 623 624
    'REMOTE_ADDR' => '127.0.0.1',
    'REQUEST_METHOD' => 'GET',
    'SERVER_NAME' => NULL,
625
    'SERVER_SOFTWARE' => NULL,
626 627 628 629 630 631
    'HTTP_USER_AGENT' => NULL,
  );
  // Replace elements of the $_SERVER array, as appropriate.
  $_SERVER = $variables + $_SERVER + $defaults;
}

632
/**
633
 * Initializes the PHP environment.
634
 */
635
function drupal_environment_initialize() {
636 637
  if (!isset($_SERVER['HTTP_REFERER'])) {
    $_SERVER['HTTP_REFERER'] = '';
638
  }
639 640 641
  if (!isset($_SERVER['SERVER_PROTOCOL']) || ($_SERVER['SERVER_PROTOCOL'] != 'HTTP/1.0' && $_SERVER['SERVER_PROTOCOL'] != 'HTTP/1.1')) {
    $_SERVER['SERVER_PROTOCOL'] = 'HTTP/1.0';
  }
642

643 644 645 646 647 648 649 650 651 652 653 654 655 656 657
  if (isset($_SERVER['HTTP_HOST'])) {
    // As HTTP_HOST is user input, ensure it only contains characters allowed
    // in hostnames. See RFC 952 (and RFC 2181).
    // $_SERVER['HTTP_HOST'] is lowercased here per specifications.
    $_SERVER['HTTP_HOST'] = strtolower($_SERVER['HTTP_HOST']);
    if (!drupal_valid_http_host($_SERVER['HTTP_HOST'])) {
      // HTTP_HOST is invalid, e.g. if containing slashes it may be an attack.
      header($_SERVER['SERVER_PROTOCOL'] . ' 400 Bad Request');
      exit;
    }
  }
  else {
    // Some pre-HTTP/1.1 clients will not send a Host header. Ensure the key is
    // defined for E_ALL compliance.
    $_SERVER['HTTP_HOST'] = '';
658 659
  }

660 661 662 663 664 665 666
  // When clean URLs are enabled, emulate ?q=foo/bar using REQUEST_URI. It is
  // not possible to append the query string using mod_rewrite without the B
  // flag (this was added in Apache 2.2.8), because mod_rewrite unescapes the
  // path before passing it on to PHP. This is a problem when the path contains
  // e.g. "&" or "%" that have special meanings in URLs and must be encoded.
  $_GET['q'] = request_path();

667 668
  // Enforce E_ALL, but allow users to set levels not part of E_ALL.
  error_reporting(E_ALL | error_reporting());
669

670 671 672
  // Override PHP settings required for Drupal to work properly.
  // sites/default/default.settings.php contains more runtime settings.
  // The .htaccess file contains settings that cannot be changed at runtime.
673

674
  // Don't escape quotes when reading files from the database, disk, etc.
675
  ini_set('magic_quotes_runtime', '0');
676 677
  // Use session cookies, not transparent sessions that puts the session id in
  // the query string.
678
  ini_set('session.use_cookies', '1');
679
  ini_set('session.use_only_cookies', '1');
680
  ini_set('session.use_trans_sid', '0');
681 682
  // Don't send HTTP headers using PHP's session handler.
  ini_set('session.cache_limiter', 'none');
683 684
  // Use httponly session cookies.
  ini_set('session.cookie_httponly', '1');
685 686 687 688

  // Set sane locale settings, to ensure consistent string, dates, times and
  // numbers handling.
  setlocale(LC_ALL, 'C');
689 690
}

691
/**
692
 * Validates that a hostname (for example $_SERVER['HTTP_HOST']) is safe.
693 694 695 696
 *
 * @return
 *  TRUE if only containing valid characters, or FALSE otherwise.
 */
697 698
function drupal_valid_http_host($host) {
  return preg_match('/^\[?(?:[a-zA-Z0-9-:\]_]+\.?)+$/', $host);
699 700
}

701
/**
702
 * Sets the base URL, cookie domain, and session name from configuration.
703
 */
704
function drupal_settings_initialize() {
705 706
  global $base_url, $base_path, $base_root;

707
  // Export these settings.php variables to the global namespace.
708
  global $databases, $cookie_domain, $conf, $installed_profile, $update_free_access, $db_url, $db_prefix, $drupal_hash_salt, $is_https, $base_secure_url, $base_insecure_url;
Dries's avatar
Dries committed
709 710
  $conf = array();

711 712
  if (file_exists(DRUPAL_ROOT . '/' . conf_path() . '/settings.php')) {
    include_once DRUPAL_ROOT . '/' . conf_path() . '/settings.php';
713
  }
714
  $is_https = isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) == 'on';
715 716 717 718

  if (isset($base_url)) {
    // Parse fixed base URL from settings.php.
    $parts = parse_url($base_url);
719 720 721
    if (!isset($parts['path'])) {
      $parts['path'] = '';
    }
722
    $base_path = $parts['path'] . '/';
723 724 725 726
    // Build $base_root (everything until first slash after "scheme://").
    $base_root = substr($base_url, 0, strlen($base_url) - strlen($parts['path']));
  }
  else {
727
    // Create base URL.
728
    $http_protocol = $is_https ? 'https' : 'http';
729
    $base_root = $http_protocol . '://' . $_SERVER['HTTP_HOST'];
730

731
    $base_url = $base_root;
732 733 734

    // $_SERVER['SCRIPT_NAME'] can, in contrast to $_SERVER['PHP_SELF'], not
    // be modified by a visitor.
735 736
    if ($dir = rtrim(dirname($_SERVER['SCRIPT_NAME']), '\/')) {
      $base_path = $dir;
737 738 739 740 741 742 743
      $base_url .= $base_path;
      $base_path .= '/';
    }
    else {
      $base_path = '/';
    }
  }
744 745
  $base_secure_url = str_replace('http://', 'https://', $base_url);
  $base_insecure_url = str_replace('https://', 'http://', $base_url);
746 747 748 749 750 751

  if ($cookie_domain) {
    // If the user specifies the cookie domain, also use it for session name.
    $session_name = $cookie_domain;
  }
  else {
752
    // Otherwise use $base_url as session name, without the protocol
753
    // to use the same session identifiers across HTTP and HTTPS.
754
    list( , $session_name) = explode('://', $base_url, 2);
755 756
    // HTTP_HOST can be modified by a visitor, but we already sanitized it
    // in drupal_settings_initialize().
757
    if (!empty($_SERVER['HTTP_HOST'])) {
758
      $cookie_domain = $_SERVER['HTTP_HOST'];
759 760 761 762 763 764 765
      // Strip leading periods, www., and port numbers from cookie domain.
      $cookie_domain = ltrim($cookie_domain, '.');
      if (strpos($cookie_domain, 'www.') === 0) {
        $cookie_domain = substr($cookie_domain, 4);
      }
      $cookie_domain = explode(':', $cookie_domain);
      $cookie_domain = '.' . $cookie_domain[0];
766 767 768 769 770 771 772
    }
  }
  // Per RFC 2109, cookie domains must contain at least one dot other than the
  // first. For hosts such as 'localhost' or IP Addresses we don't set a cookie domain.
  if (count(explode('.', $cookie_domain)) > 2 && !is_numeric(str_replace('.', '', $cookie_domain))) {
    ini_set('session.cookie_domain', $cookie_domain);
  }
773 774 775 776 777 778 779 780 781 782
  // To prevent session cookies from being hijacked, a user can configure the
  // SSL version of their website to only transfer session cookies via SSL by
  // using PHP's session.cookie_secure setting. The browser will then use two
  // separate session cookies for the HTTPS and HTTP versions of the site. So we
  // must use different session identifiers for HTTPS and HTTP to prevent a
  // cookie collision.
  if ($is_https) {
    ini_set('session.cookie_secure', TRUE);
  }
  $prefix = ini_get('session.cookie_secure') ? 'SSESS' : 'SESS';
783
  session_name($prefix . substr(hash('sha256', $session_name), 0, 32));
784 785
}

Dries's avatar
Dries committed
786
/**
787 788 789 790
 * Returns and optionally sets the filename for a system resource.
 *
 * The filename, whether provided, cached, or retrieved from the database, is
 * only returned if the file exists.
Dries's avatar
Dries committed
791
 *
Dries's avatar
Dries committed
792 793 794 795 796 797 798 799 800 801 802 803
 * This function plays a key role in allowing Drupal's resources (modules
 * and themes) to be located in different places depending on a site's
 * configuration. For example, a module 'foo' may legally be be located
 * in any of these three places:
 *
 * modules/foo/foo.module
 * sites/all/modules/foo/foo.module
 * sites/example.com/modules/foo/foo.module
 *
 * Calling drupal_get_filename('module', 'foo') will give you one of
 * the above, depending on where the module is located.
 *
Dries's avatar
Dries committed
804
 * @param $type
805
 *   The type of the item (i.e. theme, theme_engine, module, profile).
Dries's avatar
Dries committed
806 807 808 809 810 811 812
 * @param $name
 *   The name of the item for which the filename is requested.
 * @param $filename
 *   The filename of the item if it is to be set explicitly rather
 *   than by consulting the database.
 *
 * @return
813
 *   The filename of the requested item or NULL if the item is not found.
Dries's avatar
Dries committed
814
 */
Dries's avatar
Dries committed
815
function drupal_get_filename($type, $name, $filename = NULL) {
816 817
  // The location of files will not change during the request, so do not use
  // drupal_static().
818
  static $files = array(), $dirs = array();
Dries's avatar
Dries committed
819

820 821 822 823 824
  // Profiles are a special case: they have a fixed location and naming.
  if ($type == 'profile') {
    $profile_filename = "profiles/$name/$name.profile";
    $files[$type][$name] = file_exists($profile_filename) ? $profile_filename : FALSE;
  }
825
  if (!isset($files[$type])) {
Dries's avatar
Dries committed
826 827 828
    $files[$type] = array();
  }

829
  if (!empty($filename) && file_exists($filename)) {
Dries's avatar
Dries committed
830 831
    $files[$type][$name] = $filename;
  }
832
  elseif (isset($files[$type][$name])) {
Dries's avatar
Dries committed
833 834
    // nothing
  }
Dries's avatar
Dries committed
835
  // Verify that we have an active database connection, before querying
836
  // the database. This is required because this function is called both
Dries's avatar
Dries committed
837 838
  // before we have a database connection (i.e. during installation) and
  // when a database connection fails.
Dries's avatar
Dries committed
839
  else {
840
    try {
841 842
      if (function_exists('db_query')) {
        $file = db_query("SELECT filename FROM {system} WHERE name = :name AND type = :type", array(':name' => $name, ':type' => $type))->fetchField();
843
        if (file_exists(DRUPAL_ROOT . '/' . $file)) {
844 845
          $files[$type][$name] = $file;
        }
846 847
      }
    }
848
    catch (Exception $e) {
849 850 851 852 853 854 855 856 857 858 859
      // The database table may not exist because Drupal is not yet installed,
      // or the database might be down. We have a fallback for this case so we
      // hide the error completely.
    }
    // Fallback to searching the filesystem if the database could not find the
    // file or the file returned by the database is not found.
    if (!isset($files[$type][$name])) {
      // We have a consistent directory naming: modules, themes...
      $dir = $type . 's';
      if ($type == 'theme_engine') {
        $dir = 'themes/engines';
860
        $extension = 'engine';
861 862
      }
      elseif ($type == 'theme') {
863
        $extension = 'info';
864 865
      }
      else {
866
        $extension = $type;
867 868
      }

869 870 871 872 873 874 875 876 877 878 879 880 881
      if (!isset($dirs[$dir][$extension])) {
        $dirs[$dir][$extension] = TRUE;
        if (!function_exists('drupal_system_listing')) {
          require_once DRUPAL_ROOT . '/includes/common.inc';
        }
        // Scan the appropriate directories for all files with the requested
        // extension, not just the file we are currently looking for. This
        // prevents unnecessary scans from being repeated when this function is
        // called more than once in the same page request.
        $matches = drupal_system_listing("/^" . DRUPAL_PHP_FUNCTION_PATTERN . "\.$extension$/", $dir, 'name', 0);
        foreach ($matches as $matched_name => $file) {
          $files[$type][$matched_name] = $file->uri;
        }
Dries's avatar
Dries committed
882 883 884 885
      }
    }
  }

886 887 888
  if (isset($files[$type][$name])) {
    return $files[$type][$name];
  }
Dries's avatar
Dries committed
889 890
}

891
/**
892
 * Loads the persistent variable table.
893 894
 *
 * The variable table is composed of values that have been saved in the table
895 896
 * with variable_set() as well as those explicitly specified in the
 * configuration file.
897
 */
898
function variable_initialize($conf = array()) {
899 900
  // NOTE: caching the variables improves performance by 20% when serving
  // cached pages.
901
  if ($cached = cache_get('variables', 'cache_bootstrap')) {
902
    $variables = $cached->data;
903 904
  }
  else {
905 906 907 908 909 910 911 912 913 914 915 916 917 918
    // Cache miss. Avoid a stampede.
    $name = 'variable_init';
    if (!lock_acquire($name, 1)) {
      // Another request is building the variable cache.
      // Wait, then re-run this function.
      lock_wait($name);
      return variable_initialize($conf);
    }
    else {
      // Proceed with variable rebuild.
      $variables = array_map('unserialize', db_query('SELECT name, value FROM {variable}')->fetchAllKeyed());
      cache_set('variables', $variables, 'cache_bootstrap');
      lock_release($name);
    }
919 920 921 922
  }

  foreach ($conf as $name => $value) {
    $variables[$name] = $value;
923 924
  }

925
  return $variables;
926 927
}

928
/**
929 930 931 932 933
 * Returns a persistent variable.
 *
 * Case-sensitivity of the variable_* functions depends on the database
 * collation used. To avoid problems, always use lower case for persistent
 * variable names.
934 935 936 937 938
 *
 * @param $name
 *   The name of the variable to return.
 * @param $default
 *   The default value to use if this variable has never been set.
939
 *
940
 * @return
941
 *   The value of the variable. Unserialization is taken care of as necessary.
942
 *
943 944
 * @see variable_del()
 * @see variable_set()
945
 */
946
function variable_get($name, $default = NULL) {
947 948 949 950 951
  global $conf;

  return isset($conf[$name]) ? $conf[$name] : $default;
}

952
/**
953 954 955 956 957
 * Sets a persistent variable.
 *
 * Case-sensitivity of the variable_* functions depends on the database
 * collation used. To avoid problems, always use lower case for persistent
 * variable names.
958 959 960 961 962 963
 *
 * @param $name
 *   The name of the variable to set.
 * @param $value
 *   The value to set. This can be any PHP data type; these functions take care
 *   of serialization as necessary.
964
 *
965 966
 * @see variable_del()
 * @see variable_get()
967
 */
968 969 970
function variable_set($name, $value) {
  global $conf;

971
  db_merge('variable')->key(array('name' => $name))->fields(array('value' => serialize($value)))->execute();
972

973
  cache_clear_all('variables', 'cache_bootstrap');
974 975 976 977

  $conf[$name] = $value;
}

978
/**
979 980 981 982 983
 * Unsets a persistent variable.
 *
 * Case-sensitivity of the variable_* functions depends on the database
 * collation used. To avoid problems, always use lower case for persistent
 * variable names.
984 985 986
 *
 * @param $name
 *   The name of the variable to undefine.
987
 *
988 989
 * @see variable_get()
 * @see variable_set()
990
 */
991
function variable_del($name) {
Dries's avatar
Dries committed
992 993
  global $conf;

994 995 996
  db_delete('variable')
    ->condition('name', $name)
    ->execute();
997
  cache_clear_all('variables', 'cache_bootstrap');
998

Dries's avatar
Dries committed
999
  unset($conf[$name]);
1000 1001
}

1002
/**
1003
 * Retrieves the current page from the cache.
1004
 *
1005 1006 1007 1008 1009
 * Note: we do not serve cached pages to authenticated users, or to anonymous
 * users when $_SESSION is non-empty. $_SESSION may contain status messages
 * from a form submission, the contents of a shopping cart, or other user-
 * specific content that should not be cached and displayed to other users.
 *
1010 1011 1012 1013
 * @param $check_only
 *   (optional) Set to TRUE to only return whether a previous call found a
 *   cache entry.
 *
1014
 * @return
1015
 *   The cache object, if the page was found in the cache, NULL otherwise.
1016
 */
1017
function drupal_page_get_cache($check_only = FALSE) {
1018
  global $base_root;
1019 1020 1021 1022 1023
  static $cache_hit = FALSE;

  if ($check_only) {
    return $cache_hit;
  }
1024

1025
  if (drupal_page_is_cacheable()) {
1026 1027 1028 1029 1030
    $cache = cache_get($base_root . request_uri(), 'cache_page');
    if ($cache !== FALSE) {
      $cache_hit = TRUE;
    }
    return $cache;
1031
  }
1032 1033 1034
}

/**
1035
 * Determines the cacheability of the current page.
1036 1037
 *
 * @param $allow_caching
1038 1039
 *   Set to FALSE if you want to prevent this page to get cached.
 *
1040
 * @return
1041
 *   TRUE if the current page can be cached, FALSE otherwise.
1042 1043 1044 1045 1046
 */
function drupal_page_is_cacheable($allow_caching = NULL) {
  $allow_caching_static = &drupal_static(__FUNCTION__, TRUE);
  if (isset($allow_caching)) {
    $allow_caching_static = $allow_caching;
1047
  }
1048 1049

  return $allow_caching_static && ($_SERVER['REQUEST_METHOD'] == 'GET' || $_SERVER['REQUEST_METHOD'] == 'HEAD')
1050
    && !drupal_is_cli();
1051 1052
}

1053
/**
1054
 * Invokes a bootstrap hook in all bootstrap modules that implement it.
1055 1056
 *
 * @param $hook
1057
 *   The name of the bootstrap hook to invoke.
1058 1059
 *
 * @see bootstrap_hooks()
1060 1061
 */
function bootstrap_invoke_all($hook) {
1062
  // Bootstrap modules should have been loaded when this function is called, so
1063 1064 1065 1066 1067 1068
  // we don't need to tell module_list() to reset its internal list (and we
  // therefore leave the first parameter at its default value of FALSE). We
  // still pass in TRUE for the second parameter, though; in case this is the
  // first time during the bootstrap that module_list() is called, we want to
  // make sure that its internal cache is primed with the bootstrap modules
  // only.
1069
  foreach (module_list(FALSE, TRUE) as $module) {
1070 1071 1072 1073 1074
    drupal_load('module', $module);
    module_invoke($module, $hook);
  }
}

Dries's avatar
Dries committed
1075
/**
1076 1077 1078
 * Includes a file with the provided type and name.
 *
 * This prevents including a theme, engine, module, etc., more than once.
Dries's avatar
Dries committed
1079 1080 1081 1082 1083 1084 1085 1086 1087 1088
 *
 * @param $type
 *   The type of item to load (i.e. theme, theme_engine, module).
 * @param $name
 *   The name of the item to load.
 *
 * @return
 *   TRUE if the item is loaded or has already been loaded.
 */
function drupal_load($type, $name) {
1089 1090 1091
  // Once a file is included this can't be reversed during a request so do not
  // use drupal_static() here.
  static $files = array();
Dries's avatar
Dries committed
1092

1093
  if (isset($files[$type][$name])) {
Dries's avatar
Dries committed
1094 1095 1096 1097 1098 1099
    return TRUE;
  }

  $filename = drupal_get_filename($type, $name);

  if ($filename) {
1100
    include_once DRUPAL_ROOT . '/' . $filename;
Dries's avatar
Dries committed
1101 1102 1103 1104 1105 1106 1107 1108
    $files[$type][$name] = TRUE;

    return TRUE;
  }

  return FALSE;
}

1109
/**
1110
 * Sets an HTTP response header for the current page.
1111 1112 1113 1114 1115
 *
 * Note: When sending a Content-Type header, always include a 'charset' type,
 * too. This is necessary to avoid security bugs (e.g. UTF-7 XSS).
 *
 * @param $name
1116
 *   The HTTP header name, or the special 'Status' header name.
1117
 * @param $value
1118 1119 1120
 *   The HTTP header value; if equal to FALSE, the specified header is unset.
 *   If $name is 'Status', this is expected to be a status code followed by a
 *   reason phrase, e.g. "404 Not Found".
1121 1122 1123
 * @param $append
 *   Whether to append the value to an existing header or to replace it.
 */
1124
function drupal_add_http_header($name, $value, $append = FALSE) {
1125
  // The headers as name/value pairs.
1126
  $headers = &drupal_static('drupal_http_headers', array());
1127

1128
  $name_lower = strtolower($name);
1129
  _drupal_set_preferred_header_name($name);
1130

1131
  if ($value === FALSE) {
1132
    $headers[$name_lower] = FALSE;
1133
  }
1134
  elseif (isset($headers[$name_lower]) && $append) {
1135 1136
    // Multiple headers with identical names may be combined using comma (RFC
    // 2616, section 4.2).
1137
    $headers[$name_lower] .= ',' . $value;
1138 1139
  }
  else {
1140
    $headers[$name_lower] = $value;