common.lib.php

一个用PHP编写的

<?php
/* $Id: common.lib.php 10051 2007-03-02 17:22:14Z lem9 $ */
// vim: expandtab sw=4 ts=4 sts=4:

/**
 * Misc stuff and functions used by almost all the scripts.
 * Among other things, it contains the advanced authentication work.
 */

/**
 * Order of sections for common.lib.php:
 *
 * the include of libraries/defines_mysql.lib.php must be after the connection
 * to db to get the MySql version
 *
 * the authentication libraries must be before the connection to db
 *
 * ... so the required order is:
 *
 * LABEL_definition_of_functions
 *  - definition of functions
 * LABEL_variables_init
 *  - init some variables always needed
 * LABEL_parsing_config_file
 *  - parsing of the config file
 * LABEL_loading_language_file
 *  - loading language file
 * LABEL_theme_setup
 *  - setting up themes
 *
 * - load of mysql extension (if necessary) label_loading_mysql
 * - loading of an authentication library label_
 * - db connection
 * - authentication work
 * - load of the libraries/defines_mysql.lib.php library to get the MySQL
 *   release number
 */

/**
 * For now, avoid warnings of E_STRICT mode
 * (this must be done before function definitions)
 */

if (defined('E_STRICT')) {
    $old_error_reporting = error_reporting(0);
    if ($old_error_reporting & E_STRICT) {
        error_reporting($old_error_reporting ^ E_STRICT);
    } else {
        error_reporting($old_error_reporting);
    }
    unset($old_error_reporting);
}

/**
 * Avoid object cloning errors
 */

@ini_set('zend.ze1_compatibility_mode',false);

/**
 * Avoid problems with magic_quotes_runtime
 */

@ini_set('magic_quotes_runtime',false);


/******************************************************************************/
/* definition of functions         LABEL_definition_of_functions              */
/**
 * Removes insecure parts in a path; used before include() or
 * require() when a part of the path comes from an insecure source
 * like a cookie or form.
 *
 * @param    string  The path to check
 *
 * @return   string  The secured path
 *
 * @access  public
 * @author  Marc Delisle ([e-mail])
 */
function PMA_securePath($path)
{
    // change .. to .
    $path = preg_replace('@\.\.*@', '.', $path);

    return $path;
} // end function

/**
 * returns count of tables in given db
 *
 * @param   string  $db database to count tables for
 * @return  integer count of tables in $db
 */
function PMA_getTableCount($db)
{
    $tables = PMA_DBI_try_query(
        'SHOW TABLES FROM ' . PMA_backquote($db) . ';',
        null, PMA_DBI_QUERY_STORE);
    if ($tables) {
        $num_tables = PMA_DBI_num_rows($tables);
        PMA_DBI_free_result($tables);
    } else {
        $num_tables = 0;
    }

    return $num_tables;
}

/**
 * Converts numbers like 10M into bytes
 * Used with permission from Moodle (http://moodle.org) by Martin Dougiamas
 * (renamed with PMA prefix to avoid double definition when embedded
 * in Moodle)
 *
 * @param   string  $size
 * @return  integer $size
 */
function PMA_get_real_size($size = 0)
{
    if (!$size) {
        return 0;
    }
    $scan['MB'] = 1048576;
    $scan['Mb'] = 1048576;
    $scan['M']  = 1048576;
    $scan['m']  = 1048576;
    $scan['KB'] =    1024;
    $scan['Kb'] =    1024;
    $scan['K']  =    1024;
    $scan['k']  =    1024;

    while (list($key) = each($scan)) {
        if ((strlen($size) > strlen($key))
          && (substr($size, strlen($size) - strlen($key)) == $key)) {
            $size = substr($size, 0, strlen($size) - strlen($key)) * $scan[$key];
            break;
        }
    }
    return $size;
} // end function PMA_get_real_size()

/**
 * loads php module
 *
 * @uses    PHP_OS
 * @uses    extension_loaded()
 * @uses    ini_get()
 * @uses    function_exists()
 * @uses    ob_start()
 * @uses    phpinfo()
 * @uses    strip_tags()
 * @uses    ob_get_contents()
 * @uses    ob_end_clean()
 * @uses    preg_match()
 * @uses    strtoupper()
 * @uses    substr()
 * @uses    dl()
 * @param   string  $module name if module to load
 * @return  boolean success loading module
 */
function PMA_dl($module)
{
    static $dl_allowed = null;

    if (extension_loaded($module)) {
        return true;
    }

    if (null === $dl_allowed) {
        if (!@ini_get('safe_mode')
          && @ini_get('enable_dl')
          && @function_exists('dl')) {
            ob_start();
            phpinfo(INFO_GENERAL); /* Only general info */
            $a = strip_tags(ob_get_contents());
            ob_end_clean();
            if (preg_match('@Thread Safety[[:space:]]*enabled@', $a)) {
                if (preg_match('@Server API[[:space:]]*\(CGI\|CLI\)@', $a)) {
                    $dl_allowed = true;
                } else {
                    $dl_allowed = false;
                }
            } else {
                $dl_allowed = true;
            }
        } else {
            $dl_allowed = false;
        }
    }

    if (!$dl_allowed) {
        return false;
    }

    /* Once we require PHP >= 4.3, we might use PHP_SHLIB_SUFFIX here */
    if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
        $module_file = 'php_' . $module . '.dll';
    } elseif (PHP_OS=='HP-UX') {
        $module_file = $module . '.sl';
    } else {
        $module_file = $module . '.so';
    }

    return @dl($module_file);
}

/**
 * merges array recursive like array_merge_recursive() but keyed-values are
 * always overwritten.
 *
 * array PMA_array_merge_recursive(array $array1[, array $array2[, array ...]])
 *
 * @see     http://php.net/array_merge
 * @see     http://php.net/array_merge_recursive
 * @uses    func_num_args()
 * @uses    func_get_arg()
 * @uses    is_array()
 * @uses    call_user_func_array()
 * @param   array   array to merge
 * @param   array   array to merge
 * @param   array   ...
 * @return  array   merged array
 */
function PMA_array_merge_recursive()
{
    switch(func_num_args()) {
        case 0 :
            return false;
            break;
        case 1 :
            // when does that happen?
            return func_get_arg(0);
            break;
        case 2 :
            $args = func_get_args();
            if (!is_array($args[0]) || !is_array($args[1])) {
                return $args[1];
            }
            foreach ($args[1] as $key2 => $value2) {
                if (isset($args[0][$key2]) && !is_int($key2)) {
                    $args[0][$key2] = PMA_array_merge_recursive($args[0][$key2],
                        $value2);
                } else {
                    // we erase the parent array, otherwise we cannot override a directive that
                    // contains array elements, like this:
                    // (in config.default.php) $cfg['ForeignKeyDropdownOrder'] = array('id-content','content-id');
                    // (in config.inc.php) $cfg['ForeignKeyDropdownOrder'] = array('content-id');
                    if (is_int($key2) && $key2 == 0) {
                        unset($args[0]);
                    }
                    $args[0][$key2] = $value2;
                }
            }
            return $args[0];
            break;
        default :
            $args = func_get_args();
            $args[1] = PMA_array_merge_recursive($args[0], $args[1]);
            array_shift($args);
            return call_user_func_array('PMA_array_merge_recursive', $args);
            break;
    }
}

/**
 * calls $function for every element in $array recursively
 *
 * this function is protected against deep recursion attack CVE-2006-1549,
 * 1000 seems to be more than enough
 *
 * @see http://www.php-security.org/MOPB/MOPB-02-2007.html
 * @see http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-1549
 *
 * @param   array   $array      array to walk
 * @param   string  $function   function to call for every array element
 */
function PMA_arrayWalkRecursive(&$array, $function, $apply_to_keys_also = false)
{
     static $recursive_counter = 0;
     if (++$recursive_counter > 1000) {
             die('possible deep recursion attack');
     }

    foreach ($array as $key => $value) {
        if (is_array($value)) {
            PMA_arrayWalkRecursive($array[$key], $function, $apply_to_keys_also);
        } else {
            $array[$key] = $function($value);
        }

        if ($apply_to_keys_also && is_string($key)) {
            $new_key = $function($key);
            if ($new_key != $key) {
                $array[$new_key] = $array[$key];
                unset($array[$key]);
            }
        }
    }
    $recursive_counter++;
}

/**
 * boolean phpMyAdmin.PMA_checkPageValidity(string &$page, array $whitelist)
 *
 * checks given given $page against given $whitelist and returns true if valid
 * it ignores optionaly query paramters in $page (script.php?ignored)
 *
 * @uses    in_array()
 * @uses    urldecode()
 * @uses    substr()
 * @uses    strpos()
 * @param   string  &$page      page to check
 * @param   array   $whitelist  whitelist to check page against
 * @return  boolean whether $page is valid or not (in $whitelist or not)
 */
function PMA_checkPageValidity(&$page, $whitelist)
{
    if (! isset($page) || !is_string($page)) {
        return false;
    }

    if (in_array($page, $whitelist)) {
        return true;
    } elseif (in_array(substr($page, 0, strpos($page . '?', '?')), $whitelist)) {
        return true;
    } else {
        $_page = urldecode($page);
        if (in_array(substr($_page, 0, strpos($_page . '?', '?')), $whitelist)) {
            return true;
        }
    }
    return false;
}

/**
 * trys to find the value for the given environment vriable name
 *
 * searchs in $_SERVER, $_ENV than trys getenv() and apache_getenv()
 * in this order
 *
 * @param   string  $var_name   variable name
 * @return  string  value of $var or empty string
 */
function PMA_getenv($var_name) {
    if (isset($_SERVER[$var_name])) {
        return $_SERVER[$var_name];
    } elseif (isset($_ENV[$var_name])) {
        return $_ENV[$var_name];
    } elseif (getenv($var_name)) {
        return getenv($var_name);
    } elseif (function_exists('apache_getenv')
     && apache_getenv($var_name, true)) {
        return apache_getenv($var_name, true);
    }

    return '';
}

/**
 * include here only libraries which contain only function definitions
 * no code im main()!