silverstripe-framework/src/Core/Constants.php

<?php
/**
 * This file is the Framework constants bootstrap. It will prepare some basic common constants.
 *
 * It takes care of:
 *  - Including _ss_environment.php
 *  - Normalisation of $_SERVER values
 *  - Initialisation of necessary constants (mostly paths)
 *
 * Initialized constants:
 * - BASE_URL: Full URL to the webroot, e.g. "http://my-host.com/my-webroot" (no trailing slash).
 * - BASE_PATH: Absolute path to the webroot, e.g. "/var/www/my-webroot" (no trailing slash).
 *   See Director::baseFolder(). Can be overwritten by Config::inst()->update('Director', 'alternate_base_folder', ).
 * - TEMP_FOLDER: Absolute path to temporary folder, used for manifest and template caches. Example: "/var/tmp"
 *   See getTempFolder(). No trailing slash.
 * - MODULES_DIR: Not used at the moment
 * - MODULES_PATH: Not used at the moment
 * - THEMES_DIR: Path relative to webroot, e.g. "themes"
 * - THEMES_PATH: Absolute filepath, e.g. "/var/www/my-webroot/themes"
 * - FRAMEWORK_DIR: Path relative to webroot, e.g. "framework"
 * - FRAMEWORK_PATH:Absolute filepath, e.g. "/var/www/my-webroot/framework"
 * - FRAMEWORK_ADMIN_DIR: Path relative to webroot, e.g. "framework/admin"
 * - FRAMEWORK_ADMIN_PATH: Absolute filepath, e.g. "/var/www/my-webroot/framework/admin"
 * - THIRDPARTY_DIR: Path relative to webroot, e.g. "framework/thirdparty"
 * - THIRDPARTY_PATH: Absolute filepath, e.g. "/var/www/my-webroot/framework/thirdparty"
 * - TRUSTED_PROXY: true or false, depending on whether the X-Forwarded-* HTTP
 *   headers from the given client are trustworthy (e.g. from a reverse proxy).
 */

///////////////////////////////////////////////////////////////////////////////
// ENVIRONMENT CONFIG

/**
 * Include _ss_environment.php file
 */
//define the name of the environment file
$envFile = '_ss_environment.php';
//define the dirs to start scanning from (have to add the trailing slash)
// we're going to check the realpath AND the path as the script sees it
$dirsToCheck = array(
	realpath('.'),
	dirname($_SERVER['SCRIPT_FILENAME'])
);
//if they are the same, remove one of them
if ($dirsToCheck[0] == $dirsToCheck[1]) {
	unset($dirsToCheck[1]);
}
foreach ($dirsToCheck as $dir) {
	//check this dir and every parent dir (until we hit the base of the drive)
	// or until we hit a dir we can't read
	while(true) {
		//if it's readable, go ahead
		if (@is_readable($dir)) {
			//if the file exists, then we include it, set relevant vars and break out
			if (file_exists($dir . DIRECTORY_SEPARATOR . $envFile)) {
				define('SS_ENVIRONMENT_FILE', $dir . DIRECTORY_SEPARATOR . $envFile);
				include_once(SS_ENVIRONMENT_FILE);
				//break out of BOTH loops because we found the $envFile
				break(2);
			}
		}
		else {
			//break out of the while loop, we can't read the dir
			break;
		}
		if (dirname($dir) == $dir) {
			// here we need to check that the path of the last dir and the next one are
			// not the same, if they are, we have hit the root of the drive
			break;
		}
		//go up a directory
		$dir = dirname($dir);
	}
}

/**
 * Validate whether the request comes directly from a trusted server or not
 * This is necessary to validate whether or not the values of X-Forwarded-
 * or Client-IP HTTP headers can be trusted
 */
if(!defined('TRUSTED_PROXY')) {
	$trusted = true; // will be false by default in a future release

	if(getenv('BlockUntrustedProxyHeaders') // Legacy setting (reverted from documentation)
		|| getenv('BlockUntrustedIPs') // Documented setting
		|| defined('SS_TRUSTED_PROXY_IPS')
	) {
		$trusted = false;

		if(defined('SS_TRUSTED_PROXY_IPS') && SS_TRUSTED_PROXY_IPS !== 'none') {
			if(SS_TRUSTED_PROXY_IPS === '*') {
				$trusted = true;
			} elseif(isset($_SERVER['REMOTE_ADDR'])) {
				if(!class_exists('SilverStripe\\Control\\Util\\IPUtils')) {
					require_once FRAMEWORK_PATH . '/control/IPUtils.php';
				};
				$trusted = IPUtils::checkIP($_SERVER['REMOTE_ADDR'], explode(',', SS_TRUSTED_PROXY_IPS));
			}
		}
	}

	/**
	 * Declare whether or not the connecting server is a trusted proxy
	 */
	define('TRUSTED_PROXY', $trusted);
}

/**
 * A blank HTTP_HOST value is used to detect command-line execution.
 * We update the $_SERVER variable to contain data consistent with the rest of the application.
 */
if(!isset($_SERVER['HTTP_HOST'])) {
	// HTTP_HOST, REQUEST_PORT, SCRIPT_NAME, and PHP_SELF
	global $_FILE_TO_URL_MAPPING;
	if(isset($_FILE_TO_URL_MAPPING)) {
		$fullPath = $testPath = realpath($_SERVER['SCRIPT_FILENAME']);
		while($testPath && $testPath != '/' && !preg_match('/^[A-Z]:\\\\$/', $testPath)) {
			if(isset($_FILE_TO_URL_MAPPING[$testPath])) {
				$url = $_FILE_TO_URL_MAPPING[$testPath]
					. str_replace(DIRECTORY_SEPARATOR, '/', substr($fullPath,strlen($testPath)));

				$components = parse_url($url);
				$_SERVER['HTTP_HOST'] = $components['host'];
				if(!empty($components['port'])) $_SERVER['HTTP_HOST'] .= ':' . $components['port'];
				$_SERVER['SCRIPT_NAME'] = $_SERVER['PHP_SELF'] = $components['path'];
				if(!empty($components['port'])) $_SERVER['REQUEST_PORT'] = $components['port'];
				break;
			}
			$testPath = dirname($testPath);
		}
	}

	// Everything else
	$serverDefaults = array(
		'SERVER_PROTOCOL' => 'HTTP/1.1',
		'HTTP_ACCEPT' => 'text/plain;q=0.5',
		'HTTP_ACCEPT_LANGUAGE' => '*;q=0.5',
		'HTTP_ACCEPT_ENCODING' => '',
		'HTTP_ACCEPT_CHARSET' => 'ISO-8859-1;q=0.5',
		'SERVER_SIGNATURE' => 'Command-line PHP/' . phpversion(),
		'SERVER_SOFTWARE' => 'PHP/' . phpversion(),
		'SERVER_ADDR' => '127.0.0.1',
		'REMOTE_ADDR' => '127.0.0.1',
		'REQUEST_METHOD' => 'GET',
		'HTTP_USER_AGENT' => 'CLI',
	);

	$_SERVER = array_merge($serverDefaults, $_SERVER);

	/**
	 * If we have an HTTP_HOST value, then we're being called from the webserver and there are some things that
	 * need checking
	 */
} else {

	/**
	 * Fix HTTP_HOST from reverse proxies
	 */
	$trustedProxyHeader = (defined('SS_TRUSTED_PROXY_HOST_HEADER'))
		? SS_TRUSTED_PROXY_HOST_HEADER
		: 'HTTP_X_FORWARDED_HOST';

	if (TRUSTED_PROXY && !empty($_SERVER[$trustedProxyHeader])) {
		// Get the first host, in case there's multiple separated through commas
		$_SERVER['HTTP_HOST'] = strtok($_SERVER[$trustedProxyHeader], ',');
	}
}

// Filter by configured allowed hosts
if (defined('SS_ALLOWED_HOSTS') && php_sapi_name() !== "cli") {
	$all_allowed_hosts = explode(',', SS_ALLOWED_HOSTS);
	if (!isset($_SERVER['HTTP_HOST']) || !in_array($_SERVER['HTTP_HOST'], $all_allowed_hosts)) {
		header('HTTP/1.1 400 Invalid Host', true, 400);
		die();
	}
}

/**
 * Define system paths
 */
// Determine BASE_PATH based on the composer autoloader
if(!defined('BASE_PATH')) {
	foreach(debug_backtrace() as $backtraceItem) {
		if(preg_match('#^(.*)\/vendor/composer/autoload_real.php#', $backtraceItem['file'], $matches)) {
			define('BASE_PATH', $matches[1]);
			break;
		}
	}
}

// Determine BASE_PATH by assuming that this file is framework/core/Core.php
if(!defined('BASE_PATH')) {
	//  we can then determine the base path
	$candidateBasePath = rtrim(dirname(dirname(dirname(__FILE__))), DIRECTORY_SEPARATOR);
	// We can't have an empty BASE_PATH.  Making it / means that double-slashes occur in places but that's benign.
	// This likely only happens on chrooted environemnts
	if($candidateBasePath == '') $candidateBasePath = DIRECTORY_SEPARATOR;
	define('BASE_PATH', $candidateBasePath);
}
if(!defined('BASE_URL')) {
	// Determine the base URL by comparing SCRIPT_NAME to SCRIPT_FILENAME and getting common elements
	$path = realpath($_SERVER['SCRIPT_FILENAME']);
	if(substr($path, 0, strlen(BASE_PATH)) == BASE_PATH) {
		$urlSegmentToRemove = substr($path, strlen(BASE_PATH));
		if(substr($_SERVER['SCRIPT_NAME'], -strlen($urlSegmentToRemove)) == $urlSegmentToRemove) {
			$baseURL = substr($_SERVER['SCRIPT_NAME'], 0, -strlen($urlSegmentToRemove));
			define('BASE_URL', rtrim($baseURL, DIRECTORY_SEPARATOR));
		}
	}

	// If that didn't work, failover to the old syntax.  Hopefully this isn't necessary, and maybe
	// if can be phased out?
	if(!defined('BASE_URL')) {
		$dir = (strpos($_SERVER['SCRIPT_NAME'], 'index.php') !== false)
			? dirname($_SERVER['SCRIPT_NAME'])
			: dirname(dirname($_SERVER['SCRIPT_NAME']));
		define('BASE_URL', rtrim($dir, DIRECTORY_SEPARATOR));
	}
}
define('MODULES_DIR', 'modules');
define('MODULES_PATH', BASE_PATH . '/' . MODULES_DIR);
define('THEMES_DIR', 'themes');
define('THEMES_PATH', BASE_PATH . '/' . THEMES_DIR);
// Relies on this being in a subdir of the framework.
// If it isn't, or is symlinked to a folder with a different name, you must define FRAMEWORK_DIR

define('FRAMEWORK_PATH', realpath(__DIR__ . '/../'));
if(strpos(FRAMEWORK_PATH, BASE_PATH) === 0) {
	define('FRAMEWORK_DIR', trim(substr(FRAMEWORK_PATH, strlen(BASE_PATH)), DIRECTORY_SEPARATOR));
	$frameworkDirSlashSuffix = FRAMEWORK_DIR ? FRAMEWORK_DIR . '/' : '';
} else {
	throw new Exception("Path error: FRAMEWORK_PATH " . FRAMEWORK_PATH . " not within BASE_PATH " . BASE_PATH);
}

define('FRAMEWORK_ADMIN_DIR', $frameworkDirSlashSuffix . 'admin');
define('FRAMEWORK_ADMIN_PATH', FRAMEWORK_PATH . '/admin');

define('THIRDPARTY_DIR', $frameworkDirSlashSuffix . 'thirdparty');
define('THIRDPARTY_PATH', FRAMEWORK_PATH . '/thirdparty');

define('ADMIN_THIRDPARTY_DIR', FRAMEWORK_ADMIN_DIR . '/thirdparty');
define('ADMIN_THIRDPARTY_PATH', BASE_PATH . '/' . ADMIN_THIRDPARTY_DIR);

if(!defined('ASSETS_DIR')) {
	define('ASSETS_DIR', 'assets');
}
if(!defined('ASSETS_PATH')) {
	define('ASSETS_PATH', BASE_PATH . '/' . ASSETS_DIR);
}

///////////////////////////////////////////////////////////////////////////////
// INCLUDES

if(defined('CUSTOM_INCLUDE_PATH')) {
	$includePath = '.' . PATH_SEPARATOR . CUSTOM_INCLUDE_PATH . PATH_SEPARATOR
		. FRAMEWORK_PATH . PATH_SEPARATOR
		. FRAMEWORK_PATH . '/parsers' . PATH_SEPARATOR
		. THIRDPARTY_PATH . PATH_SEPARATOR
		. get_include_path();
} else {
	$includePath = '.' . PATH_SEPARATOR . FRAMEWORK_PATH . PATH_SEPARATOR
		. FRAMEWORK_PATH . '/parsers' . PATH_SEPARATOR
		. THIRDPARTY_PATH . PATH_SEPARATOR
		. get_include_path();
}

set_include_path($includePath);

/**
 * Define the temporary folder if it wasn't defined yet
 */
require_once 'Core/TempPath.php';

if(!defined('TEMP_FOLDER')) {
	define('TEMP_FOLDER', getTempFolder(BASE_PATH));
}