Merge chmod changes into trunk

git-svn-id: file:///svn/phpbb/trunk@8781 89ea8834-ac86-4346-8a33-228a782c2dd0

phpBB/includes/functions.php

@@ -484,6 +484,140 @@ 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.
+* The function uses bit fields to build the permissions.
+* The function sets the appropiate execute bit on directories.
+*
+* Supported constants representing bit fields are:
+*
+* CHMOD_ALL - all permissions (7)
+* CHMOD_READ - read permission (4)
+* CHMOD_WRITE - write permission (2)
+* CHMOD_EXECUTE - execute permission (1)
+*
+* 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 $perms Permissions to set
+* @return true on success, otherwise false
+*
+* @author faw, phpBB Group
+*/
+function phpbb_chmod($filename, $perms = CHMOD_READ)
+{
+	// Return if the file no longer exists.
+	if (!file_exists($filename))
+	{
+		return false;
+	}
+
+	if (!function_exists('fileowner') || !function_exists('filegroup'))
+	{
+		$file_uid = $file_gid = false;
+		$common_php_owner = $common_php_group = false;
+	}
+	else
+	{
+		// Determine owner/group of common.php file and the filename we want to change here
+		$common_php_owner = fileowner(PHPBB_ROOT_PATH . 'common.' . PHP_EXT);
+		$common_php_group = filegroup(PHPBB_ROOT_PATH . 'common.' . PHP_EXT);
+
+		$file_uid = fileowner($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));
+			{
+				$file_uid = fileowner($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));
+			{
+				$file_gid = filegroup($filename);
+			}
+		}
+	}
+
+	// And the owner and the groups PHP is running under.
+	$php_uid = (function_exists('posix_getuid')) ? @posix_getuid() : false;
+	$php_gids = (function_exists('posix_getgroups')) ? @posix_getgroups() : false;
+
+	// Who is PHP?
+	if ($file_uid === false || $file_gid === false || $php_uid === false || $php_gids === false)
+	{
+		$php = null;
+	}
+	else if ($file_uid == $php_uid /* && $common_php_owner !== false && $common_php_owner === $file_uid*/)
+	{
+		$php = 'owner';
+	}
+	else if (in_array($file_gid, $php_gids))
+	{
+		$php = 'group';
+	}
+	else
+	{
+		$php = 'other';
+	}
+
+	// Owner always has read/write permission
+	$owner = CHMOD_READ | CHMOD_WRITE;
+	if (is_dir($filename))
+	{
+		$owner |= CHMOD_EXECUTE;
+
+		// Only add execute bit to the permission if the dir needs to be readable
+		if ($perms & CHMOD_READ)
+		{
+			$perms |= CHMOD_EXECUTE;
+		}
+	}
+
+	switch ($php)
+	{
+		case null:
+		case 'owner':
+			$result = @chmod($filename, ($owner << 6) + (0 << 3) + (0 << 0));
+
+			if (!is_null($php) || (!is_readable($filename) && is_writable($filename)))
+			{
+				break;
+			}
+
+		case 'group':
+			$result = @chmod($filename, ($owner << 6) + ($perms << 3) + (0 << 0));
+
+			if (!is_null($php) || ((!($perms & CHMOD_READ) || is_readable($filename)) && (!($perms & CHMOD_WRITE) || is_writable($filename))))
+			{
+				break;
+			}
+
+		case 'other':
+			$result = @chmod($filename, ($owner << 6) + ($perms << 3) + ($perms << 0));
+
+			if (!is_null($php) || ((!($perms & CHMOD_READ) || is_readable($filename)) && (!($perms & CHMOD_WRITE) || is_writable($filename))))
+			{
+				break;
+			}
+
+		default:
+			return false;
+		break;
+	}
+
+	return $result;
+}
+
+/*
 * Checks if a path ($path) is absolute or relative
 *
 * @param string $path Path to check absoluteness of