common.inc 274 KB
Newer Older
Dries's avatar
 
Dries committed
1 2
<?php

Dries's avatar
 
Dries committed
3 4 5 6 7 8 9 10
/**
 * @file
 * Common functions that many Drupal modules will need to reference.
 *
 * The functions that are critical and need to be available even when serving
 * a cached page are instead located in bootstrap.inc.
 */

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
/**
 * @defgroup php_wrappers PHP wrapper functions
 * @{
 * Functions that are wrappers or custom implementations of PHP functions.
 *
 * Certain PHP functions should not be used in Drupal. Instead, Drupal's
 * replacement functions should be used.
 *
 * For example, for improved or more secure UTF8-handling, or RFC-compliant
 * handling of URLs in Drupal.
 *
 * For ease of use and memorizing, all these wrapper functions use the same name
 * as the original PHP function, but prefixed with "drupal_". Beware, however,
 * that not all wrapper functions support the same arguments as the original
 * functions.
 *
 * You should always use these wrapper functions in your code.
 *
 * Wrong:
 * @code
 *   $my_substring = substr($original_string, 0, 5);
 * @endcode
 *
 * Correct:
 * @code
 *   $my_substring = drupal_substr($original_string, 0, 5);
 * @endcode
 *
39
 * @}
40 41
 */

42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
/**
 * Return status for saving which involved creating a new item.
 */
define('SAVED_NEW', 1);

/**
 * Return status for saving which involved an update to an existing item.
 */
define('SAVED_UPDATED', 2);

/**
 * Return status for saving which deleted an existing item.
 */
define('SAVED_DELETED', 3);

57
/**
58
 * The default group for system CSS files added to the page.
59 60 61 62
 */
define('CSS_SYSTEM', -100);

/**
63
 * The default group for module CSS files added to the page.
64 65 66 67
 */
define('CSS_DEFAULT', 0);

/**
68
 * The default group for theme CSS files added to the page.
69 70 71
 */
define('CSS_THEME', 100);

72
/**
73
 * The default group for JavaScript libraries or jQuery plugins added
74
 * to the page.
75 76 77 78
 */
define('JS_LIBRARY', -100);

/**
79
 * The default group for module JavaScript code added to the page.
80 81 82 83
 */
define('JS_DEFAULT', 0);

/**
84
 * The default group for theme JavaScript code added to the page.
85 86 87
 */
define('JS_THEME', 100);

88 89 90 91 92
/**
 * The default group for JavaScript settings added to the page.
 */
define('JS_SETTING', 200);

93 94 95 96
/**
 * Error code indicating that the request made by drupal_http_request() exceeded
 * the specified timeout.
 */
97
define('HTTP_REQUEST_TIMEOUT', -1);
98

99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157
/**
 * Constants defining cache granularity for blocks and renderable arrays.
 *
 * Modules specify the caching patterns for their blocks using binary
 * combinations of these constants in their hook_block_info():
 *   $block[delta]['cache'] = DRUPAL_CACHE_PER_ROLE | DRUPAL_CACHE_PER_PAGE;
 * DRUPAL_CACHE_PER_ROLE is used as a default when no caching pattern is
 * specified. Use DRUPAL_CACHE_CUSTOM to disable standard block cache and
 * implement
 *
 * The block cache is cleared in cache_clear_all(), and uses the same clearing
 * policy than page cache (node, comment, user, taxonomy added or updated...).
 * Blocks requiring more fine-grained clearing might consider disabling the
 * built-in block cache (DRUPAL_NO_CACHE) and roll their own.
 *
 * Note that user 1 is excluded from block caching.
 */

/**
 * The block should not get cached. This setting should be used:
 * - for simple blocks (notably those that do not perform any db query),
 * where querying the db cache would be more expensive than directly generating
 * the content.
 * - for blocks that change too frequently.
 */
define('DRUPAL_NO_CACHE', -1);

/**
 * The block is handling its own caching in its hook_block_view(). From the
 * perspective of the block cache system, this is equivalent to DRUPAL_NO_CACHE.
 * Useful when time based expiration is needed or a site uses a node access
 * which invalidates standard block cache.
 */
define('DRUPAL_CACHE_CUSTOM', -2);

/**
 * The block or element can change depending on the roles the user viewing the
 * page belongs to. This is the default setting for blocks, used when the block
 * does not specify anything.
 */
define('DRUPAL_CACHE_PER_ROLE', 0x0001);

/**
 * The block or element can change depending on the user viewing the page.
 * This setting can be resource-consuming for sites with large number of users,
 * and thus should only be used when DRUPAL_CACHE_PER_ROLE is not sufficient.
 */
define('DRUPAL_CACHE_PER_USER', 0x0002);

/**
 * The block or element can change depending on the page being viewed.
 */
define('DRUPAL_CACHE_PER_PAGE', 0x0004);

/**
 * The block or element is the same for every user on every page where it is visible.
 */
define('DRUPAL_CACHE_GLOBAL', 0x0008);

158
/**
159
 * Add content to a specified region.
160 161
 *
 * @param $region
162
 *   Page region the content is added to.
163
 * @param $data
164
 *   Content to be added.
165
 */
166
function drupal_add_region_content($region = NULL, $data = NULL) {
167 168
  static $content = array();

169
  if (isset($region) && isset($data)) {
170 171 172 173 174 175
    $content[$region][] = $data;
  }
  return $content;
}

/**
176
 * Get assigned content for a given region.
177 178
 *
 * @param $region
179 180
 *   A specified region to fetch content for. If NULL, all regions will be
 *   returned.
181
 * @param $delimiter
182
 *   Content to be inserted between imploded array elements.
183
 */
184 185
function drupal_get_region_content($region = NULL, $delimiter = ' ') {
  $content = drupal_add_region_content();
186 187
  if (isset($region)) {
    if (isset($content[$region]) && is_array($content[$region])) {
Steven Wittens's avatar
Steven Wittens committed
188
      return implode($delimiter, $content[$region]);
189
    }
190 191 192 193
  }
  else {
    foreach (array_keys($content) as $region) {
      if (is_array($content[$region])) {
Steven Wittens's avatar
Steven Wittens committed
194
        $content[$region] = implode($delimiter, $content[$region]);
195 196 197 198 199 200
      }
    }
    return $content;
  }
}

201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219
/**
 * Get the name of the currently active install profile.
 *
 * When this function is called during Drupal's initial installation process,
 * the name of the profile that's about to be installed is stored in the global
 * installation state. At all other times, the standard Drupal systems variable
 * table contains the name of the current profile, and we can call variable_get()
 * to determine what one is active.
 *
 * @return $profile
 *   The name of the install profile.
 */
function drupal_get_profile() {
  global $install_state;

  if (isset($install_state['parameters']['profile'])) {
    $profile = $install_state['parameters']['profile'];
  }
  else {
220
    $profile = variable_get('install_profile', 'standard');
221 222 223 224 225 226
  }

  return $profile;
}


Dries's avatar
 
Dries committed
227
/**
Dries's avatar
 
Dries committed
228
 * Set the breadcrumb trail for the current page.
Dries's avatar
 
Dries committed
229
 *
Dries's avatar
 
Dries committed
230 231 232
 * @param $breadcrumb
 *   Array of links, starting with "home" and proceeding up to but not including
 *   the current page.
Kjartan's avatar
Kjartan committed
233
 */
Dries's avatar
 
Dries committed
234
function drupal_set_breadcrumb($breadcrumb = NULL) {
235
  $stored_breadcrumb = &drupal_static(__FUNCTION__);
Dries's avatar
 
Dries committed
236

237
  if (isset($breadcrumb)) {
Dries's avatar
 
Dries committed
238 239 240 241 242
    $stored_breadcrumb = $breadcrumb;
  }
  return $stored_breadcrumb;
}

Dries's avatar
 
Dries committed
243 244 245
/**
 * Get the breadcrumb trail for the current page.
 */
Dries's avatar
 
Dries committed
246 247 248
function drupal_get_breadcrumb() {
  $breadcrumb = drupal_set_breadcrumb();

249
  if (!isset($breadcrumb)) {
Dries's avatar
 
Dries committed
250 251 252 253 254 255
    $breadcrumb = menu_get_active_breadcrumb();
  }

  return $breadcrumb;
}

Dries's avatar
Dries committed
256
/**
Dries's avatar
 
Dries committed
257
 * Add output to the head tag of the HTML page.
258
 *
259
 * This function can be called as long as the headers aren't sent. Pass no
260 261 262 263 264 265 266 267 268 269 270 271 272
 * arguments (or NULL for both) to retrieve the currently stored elements.
 *
 * @param $data
 *   A renderable array. If the '#type' key is not set then 'html_tag' will be
 *   added as the default '#type'.
 * @param $key
 *   A unique string key to allow implementations of hook_html_head_alter() to
 *   identify the element in $data. Required if $data is not NULL.
 *
 * @return
 *   An array of all stored HEAD elements.
 *
 * @see theme_html_tag()
Dries's avatar
Dries committed
273
 */
274 275
function drupal_add_html_head($data = NULL, $key = NULL) {
  $stored_head = &drupal_static(__FUNCTION__);
Dries's avatar
Dries committed
276

277 278 279 280 281 282 283 284 285 286
  if (!isset($stored_head)) {
    // Make sure the defaults, including Content-Type, come first.
    $stored_head = _drupal_default_html_head();
  }

  if (isset($data) && isset($key)) {
    if (!isset($data['#type'])) {
      $data['#type'] = 'html_tag';
    }
    $stored_head[$key] = $data;
Dries's avatar
Dries committed
287 288 289 290
  }
  return $stored_head;
}

Dries's avatar
 
Dries committed
291
/**
292 293 294 295 296 297 298 299 300 301
 * Returns elements that are always displayed in the HEAD tag of the HTML page.
 */
function _drupal_default_html_head() {
  // Add default elements. Make sure the Content-Type comes first because the
  // IE browser may be vulnerable to XSS via encoding attacks from any content
  // that comes before this META tag, such as a TITLE tag.
  $elements['system_meta_content_type'] = array(
    '#type' => 'html_tag',
    '#tag' => 'meta',
    '#attributes' => array(
302
      'charset' => 'utf-8',
303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324
    ),
    // Security: This always has to be output first.
    '#weight' => -1000,
  );
  // Show Drupal and the major version number in the META GENERATOR tag.
  // Get the major version.
  list($version, ) = explode('.', VERSION);
  $elements['system_meta_generator'] = array(
    '#type' => 'html_tag',
    '#tag' => 'meta',
    '#attributes' => array(
      'name' => 'Generator',
      'content' => 'Drupal ' . $version . ' (http://drupal.org)',
    ),
  );
  // Also send the generator in the HTTP header.
  $elements['system_meta_generator']['#attached']['drupal_add_http_header'][] = array('X-Generator', $elements['system_meta_generator']['#attributes']['content']);
  return $elements;
}

/**
 * Retrieve output to be displayed in the HEAD tag of the HTML page.
Dries's avatar
 
Dries committed
325
 */
Dries's avatar
Dries committed
326
function drupal_get_html_head() {
327 328 329
  $elements = drupal_add_html_head();
  drupal_alter('html_head', $elements);
  return drupal_render($elements);
Dries's avatar
Dries committed
330 331
}

332
/**
333 334
 * Add a feed URL for the current page.
 *
335 336
 * This function can be called as long the HTML header hasn't been sent.
 *
337
 * @param $url
338
 *   An internal system path or a fully qualified external URL of the feed.
339
 * @param $title
340
 *   The title of the feed.
341
 */
342
function drupal_add_feed($url = NULL, $title = '') {
343
  $stored_feed_links = &drupal_static(__FUNCTION__, array());
344

345
  if (isset($url)) {
346
    $stored_feed_links[$url] = theme('feed_icon', array('url' => $url, 'title' => $title));
347

348 349 350 351 352 353 354 355
    drupal_add_html_head_link(array(
      'rel' => 'alternate',
      'type' => 'application/rss+xml',
      'title' => $title,
      // Force the URL to be absolute, for consistency with other <link> tags
      // output by Drupal.
      'href' => url($url, array('absolute' => TRUE)),
    ));
356 357 358 359 360 361 362 363
  }
  return $stored_feed_links;
}

/**
 * Get the feed URLs for the current page.
 *
 * @param $delimiter
364
 *   A delimiter to split feeds by.
365 366 367 368 369 370
 */
function drupal_get_feeds($delimiter = "\n") {
  $feeds = drupal_add_feed();
  return implode($feeds, $delimiter);
}

Dries's avatar
 
Dries committed
371
/**
372
 * @defgroup http_handling HTTP handling
Dries's avatar
 
Dries committed
373
 * @{
Dries's avatar
 
Dries committed
374
 * Functions to properly handle HTTP responses.
Dries's avatar
 
Dries committed
375 376
 */

377
/**
378
 * Process a URL query parameter array to remove unwanted elements.
379 380
 *
 * @param $query
381
 *   (optional) An array to be processed. Defaults to $_GET.
382
 * @param $exclude
383 384
 *   (optional) A list of $query array keys to remove. Use "parent[child]" to
 *   exclude nested items. Defaults to array('q').
385
 * @param $parent
386 387
 *   Internal use only. Used to build the $query array key for nested items.
 *
388
 * @return
389
 *   An array containing query parameters, which can be used for url().
390
 */
391 392 393 394 395 396 397 398 399 400 401 402
function drupal_get_query_parameters(array $query = NULL, array $exclude = array('q'), $parent = '') {
  // Set defaults, if none given.
  if (!isset($query)) {
    $query = $_GET;
  }
  // If $exclude is empty, there is nothing to filter.
  if (empty($exclude)) {
    return $query;
  }
  elseif (!$parent) {
    $exclude = array_flip($exclude);
  }
403

404
  $params = array();
405
  foreach ($query as $key => $value) {
406 407 408
    $string_key = ($parent ? $parent . '[' . $key . ']' : $key);
    if (isset($exclude[$string_key])) {
      continue;
409 410
    }

411 412 413 414 415
    if (is_array($value)) {
      $params[$key] = drupal_get_query_parameters($value, $exclude, $string_key);
    }
    else {
      $params[$key] = $value;
416
    }
417 418 419 420 421
  }

  return $params;
}

422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441
/**
 * Split an URL-encoded query string into an array.
 *
 * @param $query
 *   The query string to split.
 *
 * @return
 *   An array of url decoded couples $param_name => $value.
 */
function drupal_get_query_array($query) {
  $result = array();
  if (!empty($query)) {
    foreach (explode('&', $query) as $param) {
      $param = explode('=', $param);
      $result[$param[0]] = isset($param[1]) ? rawurldecode($param[1]) : '';
    }
  }
  return $result;
}

442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464
/**
 * Parse an array into a valid, rawurlencoded query string.
 *
 * This differs from http_build_query() as we need to rawurlencode() (instead of
 * urlencode()) all query parameters.
 *
 * @param $query
 *   The query parameter array to be processed, e.g. $_GET.
 * @param $parent
 *   Internal use only. Used to build the $query array key for nested items.
 *
 * @return
 *   A rawurlencoded string which can be used as or appended to the URL query
 *   string.
 *
 * @see drupal_get_query_parameters()
 * @ingroup php_wrappers
 */
function drupal_http_build_query(array $query, $parent = '') {
  $params = array();

  foreach ($query as $key => $value) {
    $key = ($parent ? $parent . '[' . rawurlencode($key) . ']' : rawurlencode($key));
465

466
    // Recurse into children.
467
    if (is_array($value)) {
468 469 470 471 472
      $params[] = drupal_http_build_query($value, $key);
    }
    // If a query parameter value is NULL, only append its key.
    elseif (!isset($value)) {
      $params[] = $key;
473 474
    }
    else {
475 476
      // For better readability of paths in query strings, we decode slashes.
      $params[] = $key . '=' . str_replace('%2F', '/', rawurlencode($value));
477 478 479 480 481 482
    }
  }

  return implode('&', $params);
}

483
/**
484
 * Prepare a 'destination' URL query parameter for use in combination with drupal_goto().
485
 *
486 487 488 489
 * Used to direct the user back to the referring page after completing a form.
 * By default the current URL is returned. If a destination exists in the
 * previous request, that destination is returned. As such, a destination can
 * persist across multiple pages.
490 491 492 493
 *
 * @see drupal_goto()
 */
function drupal_get_destination() {
494 495 496 497 498 499
  $destination = &drupal_static(__FUNCTION__);

  if (isset($destination)) {
    return $destination;
  }

500
  if (isset($_GET['destination'])) {
501
    $destination = array('destination' => $_GET['destination']);
502 503
  }
  else {
504 505
    $path = $_GET['q'];
    $query = drupal_http_build_query(drupal_get_query_parameters());
506
    if ($query != '') {
507
      $path .= '?' . $query;
508
    }
509 510 511 512 513 514
    $destination = array('destination' => $path);
  }
  return $destination;
}

/**
515 516 517 518 519
 * Wrapper around parse_url() to parse a system URL string into an associative array, suitable for url().
 *
 * This function should only be used for URLs that have been generated by the
 * system, resp. url(). It should not be used for URLs that come from external
 * sources, or URLs that link to external resources.
520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572
 *
 * The returned array contains a 'path' that may be passed separately to url().
 * For example:
 * @code
 *   $options = drupal_parse_url($_GET['destination']);
 *   $my_url = url($options['path'], $options);
 *   $my_link = l('Example link', $options['path'], $options);
 * @endcode
 *
 * This is required, because url() does not support relative URLs containing a
 * query string or fragment in its $path argument. Instead, any query string
 * needs to be parsed into an associative query parameter array in
 * $options['query'] and the fragment into $options['fragment'].
 *
 * @param $url
 *   The URL string to parse, f.e. $_GET['destination'].
 *
 * @return
 *   An associative array containing the keys:
 *   - 'path': The path of the URL. If the given $url is external, this includes
 *     the scheme and host.
 *   - 'query': An array of query parameters of $url, if existent.
 *   - 'fragment': The fragment of $url, if existent.
 *
 * @see url()
 * @see drupal_goto()
 * @ingroup php_wrappers
 */
function drupal_parse_url($url) {
  $options = array(
    'path' => NULL,
    'query' => array(),
    'fragment' => '',
  );

  // External URLs: not using parse_url() here, so we do not have to rebuild
  // the scheme, host, and path without having any use for it.
  if (strpos($url, '://') !== FALSE) {
    // Split off everything before the query string into 'path'.
    $parts = explode('?', $url);
    $options['path'] = $parts[0];
    // If there is a query string, transform it into keyed query parameters.
    if (isset($parts[1])) {
      $query_parts = explode('#', $parts[1]);
      parse_str($query_parts[0], $options['query']);
      // Take over the fragment, if there is any.
      if (isset($query_parts[1])) {
        $options['fragment'] = $query_parts[1];
      }
    }
  }
  // Internal URLs.
  else {
573 574 575 576 577
    // parse_url() does not support relative URLs, so make it absolute. E.g. the
    // relative URL "foo/bar:1" isn't properly parsed.
    $parts = parse_url('http://example.com/' . $url);
    // Strip the leading slash that was just added.
    $options['path'] = substr($parts['path'], 1);
578 579 580 581 582 583 584
    if (isset($parts['query'])) {
      parse_str($parts['query'], $options['query']);
    }
    if (isset($parts['fragment'])) {
      $options['fragment'] = $parts['fragment'];
    }
  }
585 586 587 588 589 590 591
  // The 'q' parameter contains the path of the current page if clean URLs are
  // disabled. It overrides the 'path' of the URL when present, even if clean
  // URLs are enabled, due to how Apache rewriting rules work.
  if (isset($options['query']['q'])) {
    $options['path'] = $options['query']['q'];
    unset($options['query']['q']);
  }
592 593 594 595 596

  return $options;
}

/**
597
 * Encodes a Drupal path for use in a URL.
598
 *
599
 * For aesthetic reasons slashes are not escaped.
600
 *
601 602
 * Note that url() takes care of calling this function, so a path passed to that
 * function should not be encoded in advance.
603 604
 *
 * @param $path
605
 *   The Drupal path to encode.
606 607
 */
function drupal_encode_path($path) {
608
  return str_replace('%2F', '/', rawurlencode($path));
609 610
}

Kjartan's avatar
Kjartan committed
611
/**
Dries's avatar
 
Dries committed
612
 * Send the user to a different Drupal page.
Kjartan's avatar
Kjartan committed
613
 *
Dries's avatar
 
Dries committed
614 615
 * This issues an on-site HTTP redirect. The function makes sure the redirected
 * URL is formatted correctly.
Kjartan's avatar
Kjartan committed
616
 *
617 618 619 620 621 622
 * If a destination was specified in the current request's URI (i.e.,
 * $_GET['destination']) then it will override the $path and $options values
 * passed to this function. This provides the flexibility to build a link to
 * user/login and override the default redirection so that the user is
 * redirected to a specific path after logging in:
 * @code
623 624
 *   $query = array('destination' => "node/$node->nid");
 *   $link = l(t('Log in'), 'user/login', array('query' => $query));
625
 * @endcode
626
 *
627 628
 * Drupal will ensure that messages set by drupal_set_message() and other
 * session data are written to the database before the user is redirected.
Dries's avatar
 
Dries committed
629
 *
630 631
 * This function ends the request; use it instead of a return in your menu
 * callback.
Dries's avatar
 
Dries committed
632 633
 *
 * @param $path
634
 *   A Drupal path or a full URL.
635 636
 * @param $options
 *   An associative array of additional URL options to pass to url().
637 638 639 640 641 642 643 644
 * @param $http_response_code
 *   Valid values for an actual "goto" as per RFC 2616 section 10.3 are:
 *   - 301 Moved Permanently (the recommended value for most redirects)
 *   - 302 Found (default in Drupal and PHP, sometimes used for spamming search
 *         engines)
 *   - 303 See Other
 *   - 304 Not Modified
 *   - 305 Use Proxy
645
 *   - 307 Temporary Redirect (alternative to "503 Site Down for Maintenance")
646
 *   Note: Other values are defined by RFC 2616, but are rarely used and poorly
647
 *   supported.
648
 *
649
 * @see drupal_get_destination()
650
 * @see url()
Kjartan's avatar
Kjartan committed
651
 */
652 653
function drupal_goto($path = '', array $options = array(), $http_response_code = 302) {
  // A destination in $_GET always overrides the function arguments.
654 655
  // We do not allow absolute URLs to be passed via $_GET, as this can be an attack vector.
  if (isset($_GET['destination']) && !url_is_external($_GET['destination'])) {
656
    $destination = drupal_parse_url($_GET['destination']);
657 658 659
    $path = $destination['path'];
    $options['query'] = $destination['query'];
    $options['fragment'] = $destination['fragment'];
660 661
  }

662 663 664 665
  drupal_alter('drupal_goto', $path, $options, $http_response_code);

  // The 'Location' HTTP header must be absolute.
  $options['absolute'] = TRUE;
666

667
  $url = url($path, $options);
Kjartan's avatar
Kjartan committed
668

669
  header('Location: ' . $url, TRUE, $http_response_code);
670 671

  // The "Location" header sends a redirect status code to the HTTP daemon. In
672 673
  // some cases this can be wrong, so we make sure none of the code below the
  // drupal_goto() call gets executed upon redirection.
674
  drupal_exit($url);
Kjartan's avatar
Kjartan committed
675 676
}

677
/**
678 679 680 681 682 683
 * Deliver a "site is under maintenance" message to the browser.
 *
 * Page callback functions wanting to report a "site offline" message should
 * return MENU_SITE_OFFLINE instead of calling drupal_site_offline(). However,
 * functions that are invoked in contexts where that return value might not
 * bubble up to menu_execute_active_handler() should call drupal_site_offline().
684 685
 */
function drupal_site_offline() {
686
  drupal_deliver_page(MENU_SITE_OFFLINE);
687 688
}

Kjartan's avatar
Kjartan committed
689
/**
690 691 692 693 694 695
 * Deliver a "page not found" error to the browser.
 *
 * Page callback functions wanting to report a "page not found" message should
 * return MENU_NOT_FOUND instead of calling drupal_not_found(). However,
 * functions that are invoked in contexts where that return value might not
 * bubble up to menu_execute_active_handler() should call drupal_not_found().
Kjartan's avatar
Kjartan committed
696
 */
Dries's avatar
 
Dries committed
697
function drupal_not_found() {
698
  drupal_deliver_page(MENU_NOT_FOUND);
Dries's avatar
 
Dries committed
699
}
Dries's avatar
 
Dries committed
700

Dries's avatar
 
Dries committed
701
/**
702 703 704 705 706 707
 * Deliver a "access denied" error to the browser.
 *
 * Page callback functions wanting to report an "access denied" message should
 * return MENU_ACCESS_DENIED instead of calling drupal_access_denied(). However,
 * functions that are invoked in contexts where that return value might not
 * bubble up to menu_execute_active_handler() should call drupal_access_denied().
Dries's avatar
 
Dries committed
708 709
 */
function drupal_access_denied() {
710
  drupal_deliver_page(MENU_ACCESS_DENIED);
Dries's avatar
 
Dries committed
711 712
}

Dries's avatar
 
Dries committed
713
/**
Dries's avatar
 
Dries committed
714
 * Perform an HTTP request.
Dries's avatar
 
Dries committed
715
 *
716 717
 * This is a flexible and powerful HTTP client implementation. Correctly
 * handles GET, POST, PUT or any other HTTP requests. Handles redirects.
Dries's avatar
 
Dries committed
718 719 720
 *
 * @param $url
 *   A string containing a fully qualified URI.
721 722 723 724 725 726 727 728 729 730 731 732
 * @param array $options
 *   (optional) An array that can have one or more of the following elements:
 *   - headers: An array containing request headers to send as name/value pairs.
 *   - method: A string containing the request method. Defaults to 'GET'.
 *   - data: A string containing the request body, formatted as
 *     'param=value&param=value&...'. Defaults to NULL.
 *   - max_redirects: An integer representing how many times a redirect
 *     may be followed. Defaults to 3.
 *   - timeout: A float representing the maximum number of seconds the function
 *     call may take. The default is 30 seconds. If a timeout occurs, the error
 *     code is set to the HTTP_REQUEST_TIMEOUT constant.
 *   - context: A context resource created with stream_context_create().
733
 *
734 735 736 737 738 739 740 741 742 743
 * @return object
 *   An object that can have one or more of the following components:
 *   - request: A string containing the request body that was sent.
 *   - code: An integer containing the response status code, or the error code
 *     if an error occurred.
 *   - protocol: The response protocol (e.g. HTTP/1.1 or HTTP/1.0).
 *   - status_message: The status message from the response, if a response was
 *     received.
 *   - redirect_code: If redirected, an integer containing the initial response
 *     status code.
744 745
 *   - redirect_url: If redirected, a string containing the URL of the redirect
 *     target.
746 747 748 749 750
 *   - error: If an error occurred, the error message. Otherwise not set.
 *   - headers: An array containing the response headers as name/value pairs.
 *     HTTP header names are case-insensitive (RFC 2616, section 4.2), so for
 *     easy access the array keys are returned in lower case.
 *   - data: A string containing the response body that was received.
Dries's avatar
 
Dries committed
751
 */
752
function drupal_http_request($url, array $options = array()) {
753
  $result = new stdClass();
Dries's avatar
 
Dries committed
754

755 756 757 758
  // Parse the URL and make sure we can handle the schema.
  $uri = @parse_url($url);

  if ($uri == FALSE) {
759
    $result->error = 'unable to parse URL';
760
    $result->code = -1001;
761 762 763
    return $result;
  }

764 765 766 767 768
  if (!isset($uri['scheme'])) {
    $result->error = 'missing schema';
    $result->code = -1002;
    return $result;
  }
769

770 771 772 773 774 775 776 777
  timer_start(__FUNCTION__);

  // Merge the default options.
  $options += array(
    'headers' => array(),
    'method' => 'GET',
    'data' => NULL,
    'max_redirects' => 3,
778 779
    'timeout' => 30.0,
    'context' => NULL,
780
  );
781 782
  // stream_socket_client() requires timeout to be a float.
  $options['timeout'] = (float) $options['timeout'];
783

Dries's avatar
 
Dries committed
784 785
  switch ($uri['scheme']) {
    case 'http':
786
    case 'feed':
Dries's avatar
Dries committed
787
      $port = isset($uri['port']) ? $uri['port'] : 80;
788 789 790 791 792
      $socket = 'tcp://' . $uri['host'] . ':' . $port;
      // RFC 2616: "non-standard ports MUST, default ports MAY be included".
      // We don't add the standard port to prevent from breaking rewrite rules
      // checking the host that do not take into account the port number.
      $options['headers']['Host'] = $uri['host'] . ($port != 80 ? ':' . $port : '');
Dries's avatar
 
Dries committed
793 794
      break;
    case 'https':
795
      // Note: Only works when PHP is compiled with OpenSSL support.
Dries's avatar
Dries committed
796
      $port = isset($uri['port']) ? $uri['port'] : 443;
797 798
      $socket = 'ssl://' . $uri['host'] . ':' . $port;
      $options['headers']['Host'] = $uri['host'] . ($port != 443 ? ':' . $port : '');
Dries's avatar
 
Dries committed
799 800
      break;
    default:
801
      $result->error = 'invalid schema ' . $uri['scheme'];
802
      $result->code = -1003;
Dries's avatar
 
Dries committed
803 804 805
      return $result;
  }

806 807 808 809 810 811 812 813
  if (empty($options['context'])) {
    $fp = @stream_socket_client($socket, $errno, $errstr, $options['timeout']);
  }
  else {
    // Create a stream with context. Allows verification of a SSL certificate.
    $fp = @stream_socket_client($socket, $errno, $errstr, $options['timeout'], STREAM_CLIENT_CONNECT, $options['context']);
  }

Dries's avatar
 
Dries committed
814
  // Make sure the socket opened properly.
Dries's avatar
 
Dries committed
815
  if (!$fp) {
816 817
    // When a network error occurs, we use a negative number so it does not
    // clash with the HTTP status codes.
818
    $result->code = -$errno;
819
    $result->error = trim($errstr) ? trim($errstr) : t('Error opening socket @socket', array('@socket' => $socket));
820 821 822 823

    // Mark that this request failed. This will trigger a check of the web
    // server's ability to make outgoing HTTP requests the next time that
    // requirements checking is performed.
824
    // See system_requirements().
825 826
    variable_set('drupal_http_request_fails', TRUE);

Dries's avatar
 
Dries committed
827 828 829
    return $result;
  }

Dries's avatar
 
Dries committed
830
  // Construct the path to act on.
Dries's avatar
Dries committed
831 832
  $path = isset($uri['path']) ? $uri['path'] : '/';
  if (isset($uri['query'])) {
833
    $path .= '?' . $uri['query'];
Dries's avatar
 
Dries committed
834 835
  }

836 837 838
  // Merge the default headers.
  $options['headers'] += array(
    'User-Agent' => 'Drupal (+http://drupal.org/)',
Dries's avatar
 
Dries committed
839 840
  );

841 842 843 844
  // Only add Content-Length if we actually have any content or if it is a POST
  // or PUT request. Some non-standard servers get confused by Content-Length in
  // at least HEAD/GET requests, and Squid always requires Content-Length in
  // POST/PUT requests.
845 846 847
  $content_length = strlen($options['data']);
  if ($content_length > 0 || $options['method'] == 'POST' || $options['method'] == 'PUT') {
    $options['headers']['Content-Length'] = $content_length;
848 849 850
  }

  // If the server URL has a user then attempt to use basic authentication.
851
  if (isset($uri['user'])) {
852
    $options['headers']['Authorization'] = 'Basic ' . base64_encode($uri['user'] . (isset($uri['pass']) ? ':' . $uri['pass'] : ''));
853 854
  }

855 856 857 858 859 860
  // If the database prefix is being used by SimpleTest to run the tests in a copied
  // database then set the user-agent header to the database prefix so that any
  // calls to other Drupal pages will run the SimpleTest prefixed database. The
  // user-agent is used to ensure that multiple testing sessions running at the
  // same time won't interfere with each other as they would if the database
  // prefix were stored statically in a file or database variable.
861 862 863
  $test_info = &$GLOBALS['drupal_test_info'];
  if (!empty($test_info['test_run_id'])) {
    $options['headers']['User-Agent'] = drupal_generate_test_ua($test_info['test_run_id']);
864 865
  }

866
  $request = $options['method'] . ' ' . $path . " HTTP/1.0\r\n";
867
  foreach ($options['headers'] as $name => $value) {
868
    $request .= $name . ': ' . trim($value) . "\r\n";
Dries's avatar
 
Dries committed
869
  }
870
  $request .= "\r\n" . $options['data'];
Dries's avatar
 
Dries committed
871
  $result->request = $request;
872 873 874 875 876 877
  // Calculate how much time is left of the original timeout value.
  $timeout = $options['timeout'] - timer_read(__FUNCTION__) / 1000;
  if ($timeout > 0) {
    stream_set_timeout($fp, floor($timeout), floor(1000000 * fmod($timeout, 1)));
    fwrite($fp, $request);
  }
Dries's avatar
 
Dries committed
878

879 880 881 882 883
  // Fetch response. Due to PHP bugs like http://bugs.php.net/bug.php?id=43782
  // and http://bugs.php.net/bug.php?id=46049 we can't rely on feof(), but
  // instead must invoke stream_get_meta_data() each iteration.
  $info = stream_get_meta_data($fp);
  $alive = !$info['eof'] && !$info['timed_out'];
884
  $response = '';
885 886

  while ($alive) {
887 888 889
    // Calculate how much time is left of the original timeout value.
    $timeout = $options['timeout'] - timer_read(__FUNCTION__) / 1000;
    if ($timeout <= 0) {
890 891
      $info['timed_out'] = TRUE;
      break;
892 893
    }
    stream_set_timeout($fp, floor($timeout), floor(1000000 * fmod($timeout, 1)));
894 895 896 897
    $chunk = fread($fp, 1024);
    $response .= $chunk;
    $info = stream_get_meta_data($fp);
    $alive = !$info['eof'] && !$info['timed_out'] && $chunk;
Dries's avatar
 
Dries committed
898 899 900
  }
  fclose($fp);

901 902 903 904 905
  if ($info['timed_out']) {
    $result->code = HTTP_REQUEST_TIMEOUT;
    $result->error = 'request timed out';
    return $result;
  }
906
  // Parse response headers from the response body.
907 908 909
  // Be tolerant of malformed HTTP responses that separate header and body with
  // \n\n or \r\r instead of \r\n\r\n.
  list($response, $result->data) = preg_split("/\r\n\r\n|\n\n|\r\r/", $response, 2);
910
  $response = preg_split("/\r\n|\n|\r/", $response);
911

912
  // Parse the response status line.
913 914 915 916
  list($protocol, $code, $status_message) = explode(' ', trim(array_shift($response)), 3);
  $result->protocol = $protocol;
  $result->status_message = $status_message;

Dries's avatar
 
Dries committed
917 918
  $result->headers = array();

919 920
  // Parse the response headers.
  while ($line = trim(array_shift($response))) {
921 922 923
    list($name, $value) = explode(':', $line, 2);
    $name = strtolower($name);
    if (isset($result->headers[$name]) && $name == 'set-cookie') {
924 925
      // RFC 2109: the Set-Cookie response header comprises the token Set-
      // Cookie:, followed by a comma-separated list of one or more cookies.
926
      $result->headers[$name] .= ',' . trim($value);
927 928
    }
    else {
929
      $result->headers[$name] = trim($value);
930
    }
Dries's avatar
 
Dries committed
931 932 933
  }

  $responses = array(
934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973
    100 => 'Continue',
    101 => 'Switching Protocols',
    200 => 'OK',
    201 => 'Created',
    202 => 'Accepted',
    203 => 'Non-Authoritative Information',
    204 => 'No Content',
    205 => 'Reset Content',
    206 => 'Partial Content',
    300 => 'Multiple Choices',
    301 => 'Moved Permanently',
    302 => 'Found',
    303 => 'See Other',
    304 => 'Not Modified',
    305 => 'Use Proxy',
    307 => 'Temporary Redirect',
    400 => 'Bad Request',
    401 => 'Unauthorized',
    402 => 'Payment Required',
    403 => 'Forbidden',
    404 => 'Not Found',
    405 => 'Method Not Allowed',
    406 => 'Not Acceptable',
    407 => 'Proxy Authentication Required',
    408 => 'Request Time-out',
    409 => 'Conflict',
    410 => 'Gone',
    411 => 'Length Required',
    412 => 'Precondition Failed',
    413 => 'Request Entity Too Large',
    414 => 'Request-URI Too Large',
    415 => 'Unsupported Media Type',
    416 => 'Requested range not satisfiable',
    417 => 'Expectation Failed',
    500 => 'Internal Server Error',
    501 => 'Not Implemented',
    502 => 'Bad Gateway',
    503 => 'Service Unavailable',
    504 => 'Gateway Time-out',
    505 => 'HTTP Version not supported',
Dries's avatar
 
Dries committed
974
  );
975 976
  // RFC 2616 states that all unknown HTTP codes must be treated the same as the
  // base code in their class.
Dries's avatar
 
Dries committed
977 978 979
  if (!isset($responses[$code])) {
    $code = floor($code / 100) * 100;
  }
980
  $result->code = $code;
Dries's avatar
 
Dries committed
981 982 983 984 985 986 987 988

  switch ($code) {
    case 200: // OK
    case 304: // Not modified
      break;
    case 301: // Moved permanently
    case 302: // Moved temporarily
    case 307: // Moved temporarily
989
      $location = $result->headers['location'];
990 991 992 993 994 995
      $options['timeout'] -= timer_read(__FUNCTION__) / 1000;
      if ($options['timeout'] <= 0) {
        $result->code = HTTP_REQUEST_TIMEOUT;
        $result->error = 'request timed out';
      }
      elseif ($options['max_redirects']) {
996 997 998
        // Redirect to the new location.
        $options['max_redirects']--;
        $result = drupal_http_request($location, $options);
999
        $result->redirect_code = $code;
Dries's avatar
 
Dries committed
1000
      }
1001 1002 1003
      if (!isset($result->redirect_url)) {
        $result->redirect_url = $location;
      }
Dries's avatar
 
Dries committed
1004 1005
      break;
    default:
1006
      $result->error = $status_message;
Dries's avatar
 
Dries committed
1007 1008 1009 1010
  }

  return $result;
}
Dries's avatar
 
Dries committed
1011 1012 1013
/**
 * @} End of "HTTP handling".
 */
Dries's avatar
 
Dries committed
1014

Dries's avatar
 
Dries committed
1015
function _fix_gpc_magic(&$item) {
Dries's avatar
Dries committed
1016
  if (is_array($item)) {
Kjartan's avatar
Kjartan committed
1017 1018 1019
    array_walk($item, '_fix_gpc_magic');
  }
  else {
Kjartan's avatar
Kjartan committed
1020
    $item = stripslashes($item);
Dries's avatar
 
Dries committed
1021 1022 1023
  }
}

1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041
/**
 * Helper function to strip slashes from $_FILES skipping over the tmp_name keys
 * since PHP generates single backslashes for file paths on Windows systems.
 *
 * tmp_name does not have backslashes added see
 * http://php.net/manual/en/features.file-upload.php#42280
 */
function _fix_gpc_magic_files(&$item, $key) {
  if ($key != 'tmp_name') {
    if (is_array($item)) {
      array_walk($item, '_fix_gpc_magic_files');
    }
    else {
      $item = stripslashes($item);
    }
  }
}

Dries's avatar
 
Dries committed
1042
/**
1043
 * Fix double-escaping problems caused by "magic quotes" in some PHP installations.
Dries's avatar
 
Dries committed
1044
 */
Dries's avatar
 
Dries committed
1045
function fix_gpc_magic() {
1046
  static $fixed = FALSE;
Dries's avatar
 
Dries committed
1047
  if (!$fixed && ini_get('magic_quotes_gpc')) {
Dries's avatar
Dries committed
1048 1049 1050 1051
    array_walk($_GET, '_fix_gpc_magic');
    array_walk($_POST, '_fix_gpc_magic');
    array_walk($_COOKIE, '_fix_gpc_magic');
    array_walk($_REQUEST, '_fix_gpc_magic');
1052
    array_walk($_FILES, '_fix_gpc_magic_files');
Dries's avatar
Dries committed
1053
  }
1054
  $fixed = TRUE;
Dries's avatar
 
Dries committed
1055 1056
}

Kjartan's avatar
Kjartan committed
1057
/**
Dries's avatar
 
Dries committed
1058
 * @defgroup validation Input validation
Dries's avatar
 
Dries committed
1059
 * @{
Dries's avatar
 
Dries committed
1060
 * Functions to validate user input.
Kjartan's avatar
Kjartan committed
1061 1062
 */

1063
/**
Dries's avatar
 
Dries committed
1064 1065 1066
 * Verify the syntax of the given e-mail address.
 *
 * Empty e-mail addresses are allowed. See RFC 2822 for details.
1067
 *
Dries's avatar
 
Dries committed
1068
 * @param $mail
1069
 *   A string containing an e-mail address.
Dries's avatar
 
Dries committed
1070
 * @return
Dries's avatar
 
Dries committed
1071
 *   TRUE if the address is in a valid format.
1072
 */
Dries's avatar
 
Dries committed
1073
function valid_email_address($mail) {
1074
  return (bool)filter_var($mail, FILTER_VALIDATE_EMAIL);
1075 1076
}

Dries's avatar
 
Dries committed
1077 1078 1079
/**
 * Verify the syntax of the given URL.
 *
1080 1081
 * This function should only be used on actual URLs. It should not be used for
 * Drupal menu paths, which can contain arbitrary characters.
1082
 * Valid values per RFC 3986.
Dries's avatar
 
Dries committed
1083
 * @param $url
Dries's avatar
 
Dries committed
1084
 *   The URL to verify.
Dries's avatar
 
Dries committed
1085
 * @param $absolute
Dries's avatar
 
Dries committed
1086
 *   Whether the URL is absolute (beginning with a scheme such as "http:").
Dries's avatar
 
Dries committed
1087
 * @return
Dries's avatar
 
Dries committed
1088
 *   TRUE if the URL is in a valid format.
Dries's avatar
 
Dries committed
1089
 */
Dries's avatar
 
Dries committed
1090
function valid_url($url, $absolute = FALSE) {
1091
  if ($absolute) {
1092
    return (bool)preg_match("
1093
      /^                                                      # Start at the beginning of the text
1094
      (?:ftp|https?|feed):\/\/                                # Look for ftp, http, https or feed schemes
1095 1096 1097
      (?:                                                     # Userinfo (optional) which is typically
        (?:(?:[\w\.\-\+!$&'\(\)*\+,;=]|%[0-9a-f]{2})+:)*      # a username or a username and password
        (?:[\w\.\-\+%!$&'\(\)*\+,;=]|%[0-9a-f]{2})+@          # combination
1098
      )?
1099 1100 1101 1102 1103 1104
      (?:
        (?:[a-z0-9\-\.]|%[0-9a-f]{2})+                        # A domain name or a IPv4 address
        |(?:\[(?:[0-9a-f]{0,4}:)*(?:[0-9a-f]{0,4})\])         # or a well formed IPv6 address
      )
      (?::[0-9]+)?                                            # Server port number (optional)
      (?:[\/|\?]
1105
        (?:[\w#!:\.\?\+=&@$'~*,;\/\(\)\[\]\-]|%[0-9a-f]{2})   # The path and query (optional)
1106
      *)?
1107
    $/xi", $url);
1108 1109
  }
  else {
1110
    return (bool)preg_match("/^(?:[\w#!:\.\?\+=&@$'~*,;\/\(\)\[\]\-]|%[0-9a-f]{2})+$/i", $url);
1111
  }
Dries's avatar
 
Dries committed
1112 1113
}

1114 1115 1116 1117
/**
 * @} End of "defgroup validation".
 */

Dries's avatar
 
Dries committed
1118
/**
1119
 * Register an event for the current visitor to the flood control mechanism.
Dries's avatar
 
Dries committed
1120 1121
 *
 * @param $name
1122
 *   The name of an event.
1123 1124 1125 1126 1127
 * @param $window
 *   Optional number of seconds before this event expires. Defaults to 3600 (1
 *   hour). Typically uses the same value as the flood_is_allowed() $window
 *   parameter. Expired events are purged on cron run to prevent the flood table
 *   from growing indefinitely.
1128 1129
 * @param $identifier
 *   Optional identifier (defaults to the current user's IP address).
Dries's avatar
 
Dries committed
1130
 */
1131
function flood_register_event($name, $window = 3600, $identifier = NULL) {
1132 1133 1134
  if (!isset($identifier)) {
    $identifier = ip_address();
  }
1135 1136 1137
  db_insert('flood')
    ->fields(array(
      'event' => $name,
1138
      'identifier' => $identifier,
1139
      'timestamp' => REQUEST_TIME,
1140
      'expiration' => REQUEST_TIME + $window,
1141 1142
    ))
    ->execute();
Dries's avatar
 
Dries committed
1143 1144 1145
}

/**
1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163
 * Make the flood control mechanism forget about an event for the current visitor.
 *
 * @param $name
 *   The name of an event.
 * @param $identifier
 *   Optional identifier (defaults to the current user's IP address).
 */
function flood_clear_event($name, $identifier = NULL) {
  if (!isset($identifier)) {
    $identifier = ip_address();
  }
  db_delete('flood')
    ->condition('event', $name)
    ->condition('identifier', $identifier)
    ->execute();
}

/**
1164
 * Checks whether user is allowed to proceed with the specified event.
1165
 *
1166 1167 1168
 * Events can have thresholds saying that each user can only do that event
 * a certain number of times in a time window. This function verifies that the
 * current user has not exceeded this threshold.
Dries's avatar
 
Dries committed
1169 1170
 *
 * @param $name
1171
 *   The unique name of the event.
1172
 * @param $threshold
1173
 *   The maximum number of times each user can do this event per time window.
1174
 * @param $window
1175 1176
 *   Number of seconds in the time window for this event (default is 3600
 *   seconds, or 1 hour).
1177
 * @param $identifier
1178 1179
 *   Unique identifier of the current user. Defaults to their IP address.
 *
Dries's avatar
 
Dries committed
1180
 * @return
1181 1182
 *   TRUE if the user is allowed to proceed. FALSE if they have exceeded the
 *   threshold and should not be allowed to proceed.
Dries's avatar
 
Dries committed
1183
 */
1184 1185 1186 1187 1188
function flood_is_allowed($name, $threshold, $window = 3600, $identifier = NULL) {
  if (!isset($identifier)) {
    $identifier = ip_address();
  }
  $number = db_query("SELECT COUNT(*) FROM {flood} WHERE event = :event AND identifier = :identifier AND timestamp > :timestamp", array(
1189
    ':event' => $name,
1190 1191
    ':identifier' => $identifier,
    ':timestamp' => REQUEST_TIME - $window))
1192 1193
    ->fetchField();
  return ($number < $threshold);
Dries's avatar
 
Dries committed
1194 1195
}

1196 1197 1198 1199
/**
 * @defgroup sanitization Sanitization functions
 * @{
 * Functions to sanitize values.
1200 1201 1202
 *
 * See http://drupal.org/writing-secure-code for information
 * on writing secure code.
1203 1204
 */

Dries's avatar
Dries committed
1205
/**
1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229
 * Strips dangerous protocols (e.g. 'javascript:') from a URI.
 *
 * This function must be called for all URIs within user-entered input prior
 * to being output to an HTML attribute value. It is often called as part of
 * check_url() or filter_xss(), but those functions return an HTML-encoded
 * string, so this function can be called independently when the output needs to
 * be a plain-text string for passing to t(), l(), drupal_attributes(), or
 * another function that will call check_plain() separately.
 *
 * @param $uri
 *   A plain-text URI that might contain dangerous protocols.
 *
 * @return
 *   A plain-text URI stripped of dangerous protocols. As with all plain-text
 *   strings, this return value must not be output to an HTML page without
 *   check_plain() being called on it. However, it can be passed to functions
 *   expecting plain-text strings.
 *
 * @see check_url()
 */
function drupal_strip_dangerous_protocols($uri) {
  static $allowed_protocols;

  if (!isset($allowed_protocols)) {
1230
    $allowed_protocols = array_flip(variable_get('filter_allowed_protocols', array('ftp', 'http', 'https', 'irc', 'mailto', 'news', 'nntp', 'rtsp', 'sftp', 'ssh', 'tel', 'telnet', 'webcal')));
1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271
  }

  // Iteratively remove any invalid protocol found.
  do {
    $before = $uri;
    $colonpos = strpos($uri, ':');
    if ($colonpos > 0) {
      // We found a colon, possibly a protocol. Verify.
      $protocol = substr($uri, 0, $colonpos);
      // If a colon is preceded by a slash, question mark or hash, it cannot
      // possibly be part of the URL scheme. This must be a relative URL, which
      // inherits the (safe) protocol of the base document.
      if (preg_match('![/?#]!', $protocol)) {
        break;
      }
      // Check if this is a disallowed protocol. Per RFC2616, section 3.2.3
      // (URI Comparison) scheme comparison must be case-insensitive.
      if (!isset($allowed_protocols[strtolower($protocol)])) {
        $uri = substr($uri, $colonpos + 1);
      }
    }
  } while ($before != $uri);

  return $uri;
}

/**
 * Strips dangerous protocols (e.g. 'javascript:') from a URI and encodes it for output to an HTML attribute value.
 *
 * @param $uri
 *   A plain-text URI that might contain dangerous protocols.
 *
 * @return
 *   A URI stripped of dangerous protocols and encoded for output to an HTML
 *   attribute value. Because it is already encoded, it should not be set as a
 *   value within a $attributes array passed to drupal_attributes(), because
 *   drupal_attributes() expects those values to be plain-text strings. To pass
 *   a filtered URI to drupal_attributes(), call
 *   drupal_strip_dangerous_protocols() instead.
 *
 * @see drupal_strip_dangerous_protocols()
Dries's avatar
Dries committed
1272 1273
 */
function check_url($uri) {
1274
  return check_plain(drupal_strip_dangerous_protocols($uri));
Dries's avatar
Dries committed
1275 1276
}

1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287
/**
 * Very permissive XSS/HTML filter for admin-only use.
 *
 * Use only for fields where it is impractical to use the
 * whole filter system, but where some (mainly inline) mark-up
 * is desired (so check_plain() is not acceptable).
 *
 * Allows all tags that can be used inside an HTML body, save
 * for scripts and styles.
 */
function filter_xss_admin($string) {
1288
  return filter_xss($string, array('a', 'abbr', 'acronym', 'address', 'article', 'aside', 'b', 'bdi', 'bdo', 'big',