backport 3.2 version of phpbb_chmod() - need to be tested further...

git-svn-id: file:///svn/phpbb/branches/phpBB-3_0_0@9394 89ea8834-ac86-4346-8a33-228a782c2dd0

phpBB/includes/functions.php

@@ -461,8 +461,9 @@ function _hash_crypt_private($password, $setting, &$itoa64)
 
 /**
 * Global function for chmodding directories and files for internal use
+*
 * This function determines owner and group whom the file belongs to and user and group of PHP and then set safest possible file permissions.
-* The function determines owner and group from common.php file and sets the same to the provided file. Permissions are mapped to the group, user always has rw(x) permission.
+* The function determines owner and group from common.php file and sets the same to the provided file.
 * The function uses bit fields to build the permissions.
 * The function sets the appropiate execute bit on directories.
 *
@@ -475,24 +476,29 @@ function _hash_crypt_private($password, $setting, &$itoa64)
 *
 * NOTE: The function uses POSIX extension and fileowner()/filegroup() functions. If any of them is disabled, this function tries to build proper permissions, by calling is_readable() and is_writable() functions.
 *
-* @param $filename The file/directory to be chmodded
+* @param string	$filename	The file/directory to be chmodded
-* @param $perms Permissions to set
+* @param int	$perms		Permissions to set
-* @return true on success, otherwise false
 *
+* @return bool	true on success, otherwise false
 * @author faw, phpBB Group
 */
 function phpbb_chmod($filename, $perms = CHMOD_READ)
 {
+	static $_chmod_info;
+
 	// Return if the file no longer exists.
 	if (!file_exists($filename))
 	{
 		return false;
 	}
 
+	// Determine some common vars
+	if (empty($_chmod_info))
+	{
 		if (!function_exists('fileowner') || !function_exists('filegroup'))
 		{
-		$file_uid = $file_gid = false;
+			// No need to further determine owner/group - it is unknown
-		$common_php_owner = $common_php_group = false;
+			$_chmod_info['process'] = false;
 		}
 		else
 		{
@@ -502,49 +508,71 @@ function phpbb_chmod($filename, $perms = CHMOD_READ)
 			$common_php_owner = fileowner($phpbb_root_path . 'common.' . $phpEx);
 			$common_php_group = filegroup($phpbb_root_path . 'common.' . $phpEx);
 
-		$file_uid = fileowner($filename);
-		$file_gid = filegroup($filename);
-
-		// Try to set the owner to the same common.php has
-		if ($common_php_owner !== $file_uid && $common_php_owner !== false && $file_uid !== false)
-		{
-			// Will most likely not work
-			if (@chown($filename, $common_php_owner));
-			{
-				clearstatcache();
-				$file_uid = fileowner($filename);
-			}
-		}
-
-		// Try to set the group to the same common.php has
-		if ($common_php_group !== $file_gid && $common_php_group !== false && $file_gid !== false)
-		{
-			if (@chgrp($filename, $common_php_group));
-			{
-				clearstatcache();
-				$file_gid = filegroup($filename);
-			}
-		}
-	}
-
 			// And the owner and the groups PHP is running under.
 			$php_uid = (function_exists('posix_getuid')) ? @posix_getuid() : false;
 			$php_gids = (function_exists('posix_getgroups')) ? @posix_getgroups() : false;
 
-	// Who is PHP?
+			// If we are unable to get owner/group, then do not try to set them by guessing
-	if ($file_uid === false || $file_gid === false || $php_uid === false || $php_gids === false)
+			if (!$php_uid || empty($php_gids) || !$common_php_owner || !$common_php_group)
 			{
-		$php = NULL;
+				$_chmod_info['process'] = false;
 			}
-	else if ($file_uid == $php_uid /* && $common_php_owner !== false && $common_php_owner === $file_uid*/)
+			else
+			{
+				$_chmod_info = array(
+					'process'		=> true,
+					'common_owner'	=> $common_php_owner,
+					'common_group'	=> $common_php_group,
+					'php_uid'		=> $php_uid,
+					'php_gids'		=> $php_gids,
+				);
+			}
+		}
+	}
+
+	if ($_chmod_info['process'])
+	{
+		// Change owner
+		if (@chown($filename, $_chmod_info['common_owner']))
+		{
+			clearstatcache();
+			$file_uid = fileowner($filename);
+		}
+
+		// Change group
+		if (@chgrp($filename, $_chmod_info['common_group']))
+		{
+			clearstatcache();
+			$file_gid = filegroup($filename);
+		}
+
+		// If the file_uid/gid now match the one from common.php we can process further, else we are not able to change something
+		if ($file_uid != $_chmod_info['common_owner'] || $file_gid != $_chmod_info['common_group'])
+		{
+			$_chmod_info['process'] = false;
+		}
+	}
+
+	// Still able to process?
+	if ($_chmod_info['process'])
+	{
+		if ($file_uid == $_chmod_info['php_uid'])
 		{
 			$php = 'owner';
 		}
-	else if (in_array($file_gid, $php_gids))
+		else if (in_array($file_gid, $_chmod_info['php_gids']))
 		{
 			$php = 'group';
 		}
 		else
+		{
+			// Since we are setting the everyone bit anyway, no need to do expensive operations
+			$_chmod_info['process'] = false;
+		}
+	}
+
+	// We are not able to determine or change something
+	if (!$_chmod_info['process'])
 	{
 		$php = 'other';
 	}
@@ -564,26 +592,22 @@ function phpbb_chmod($filename, $perms = CHMOD_READ)
 
 	switch ($php)
 	{
-		case null:
 		case 'owner':
-			/* ATTENTION: if php is owner or NULL we set it to group here. This is the most failsafe combination for the vast majority of server setups.
-
 			$result = @chmod($filename, ($owner << 6) + (0 << 3) + (0 << 0));
 
 			clearstatcache();
 
-			if (!is_null($php) || (is_readable($filename) && is_writable($filename)))
+			if (is_readable($filename) && is_writable($filename))
 			{
 				break;
 			}
-		*/
 
 		case 'group':
 			$result = @chmod($filename, ($owner << 6) + ($perms << 3) + (0 << 0));
 
 			clearstatcache();
 
-			if (!is_null($php) || ((!($perms & CHMOD_READ) || is_readable($filename)) && (!($perms & CHMOD_WRITE) || is_writable($filename))))
+			if ((!($perms & CHMOD_READ) || is_readable($filename)) && (!($perms & CHMOD_WRITE) || is_writable($filename)))
 			{
 				break;
 			}
@@ -593,7 +617,7 @@ function phpbb_chmod($filename, $perms = CHMOD_READ)
 
 			clearstatcache();
 
-			if (!is_null($php) || ((!($perms & CHMOD_READ) || is_readable($filename)) && (!($perms & CHMOD_WRITE) || is_writable($filename))))
+			if ((!($perms & CHMOD_READ) || is_readable($filename)) && (!($perms & CHMOD_WRITE) || is_writable($filename)))
 			{
 				break;
 			}