Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Provides core\update\code_manager class.

 *

 * @package     core_plugin

 * @copyright   2012, 2013, 2015 David Mudrak <david@moodle.com>

 * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace core\update;

use core_component;

use coding_exception;

use moodle_exception;

use SplFileInfo;

use RecursiveDirectoryIterator;

use RecursiveIteratorIterator;

defined('MOODLE_INTERNAL') || die();

require_once($CFG->libdir.'/filelib.php');

/**

 * General purpose class managing the plugins source code files deployment

 *

 * The class is able and supposed to

 * - fetch and cache ZIP files distributed via the Moodle Plugins directory

 * - unpack the ZIP files in a temporary storage

 * - archive existing version of the plugin source code

 * - move (deploy) the plugin source code into the $CFG->dirroot

 *

 * @copyright 2015 David Mudrak <david@moodle.com>

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class code_manager {

    /** @var string full path to the Moodle app directory root */

    protected $dirroot;

    /** @var string full path to the temp directory root */

    protected $temproot;

    /**

     * Instantiate the class instance

     *

     * @param string $dirroot full path to the moodle app directory root

     * @param string $temproot full path to our temp directory

     */

    public function __construct($dirroot=null, $temproot=null) {

        global $CFG;

        if (empty($dirroot)) {

            $dirroot = $CFG->dirroot;

        }

        if (empty($temproot)) {

            // Note we are using core_plugin here as that is the valid core

            // subsystem we are part of. The namespace of this class (core\update)

            // does not match it for legacy reasons.  The data stored in the

            // temp directory are expected to survive multiple requests and

            // purging caches during the upgrade, so we make use of

            // make_temp_directory(). The contents of it can be removed if needed,

            // given the site is in the maintenance mode (so that cron is not

            // executed) and the site is not being upgraded.

            $temproot = make_temp_directory('core_plugin/code_manager');

        }

        $this->dirroot = $dirroot;

        $this->temproot = $temproot;

        $this->init_temp_directories();

    }

    /**

     * Obtain the plugin ZIP file from the given URL

     *

     * The caller is supposed to know both downloads URL and the MD5 hash of

     * the ZIP contents in advance, typically by using the API requests against

     * the plugins directory.

     *

     * @param string $url

     * @param string $md5

     * @return string|bool full path to the file, false on error

     */

    public function get_remote_plugin_zip($url, $md5) {

        // Sanitize and validate the URL.

        $url = str_replace(array("\r", "\n"), '', $url);

        if (!preg_match('|^https?://|i', $url)) {

            $this->debug('Error fetching plugin ZIP: unsupported transport protocol: '.$url);

            return false;

        }

        // The cache location for the file.

        $distfile = $this->temproot.'/distfiles/'.$md5.'.zip';

        if (is_readable($distfile) and md5_file($distfile) === $md5) {

            return $distfile;

        } else {

            @unlink($distfile);

        }

        // Download the file into a temporary location.

        $tempdir = make_request_directory();

        $tempfile = $tempdir.'/plugin.zip';

        $result = $this->download_plugin_zip_file($url, $tempfile);

        if (!$result) {

            return false;

        }

        $actualmd5 = md5_file($tempfile);

        // Make sure the actual md5 hash matches the expected one.

        if ($actualmd5 !== $md5) {

            $this->debug('Error fetching plugin ZIP: md5 mismatch.');

            return false;

        }

        // If the file is empty, something went wrong.

        if ($actualmd5 === 'd41d8cd98f00b204e9800998ecf8427e') {

            return false;

        }

        // Store the file in our cache.

        if (!rename($tempfile, $distfile)) {

            return false;

        }

        return $distfile;

    }

    /**

     * Extracts the saved plugin ZIP file.

     *

     * Returns the list of files found in the ZIP. The format of that list is

     * array of (string)filerelpath => (bool|string) where the array value is

     * either true or a string describing the problematic file.

     *

     * @see zip_packer::extract_to_pathname()

     * @param string $zipfilepath full path to the saved ZIP file

     * @param string $targetdir full path to the directory to extract the ZIP file to

     * @param string $rootdir explicitly rename the root directory of the ZIP into this non-empty value

     * @return array list of extracted files as returned by {@link zip_packer::extract_to_pathname()}

     */

    public function unzip_plugin_file($zipfilepath, $targetdir, $rootdir = '') {

        // Extract the package into a temporary location.

        $fp = get_file_packer('application/zip');

        $tempdir = make_request_directory();

        $files = $fp->extract_to_pathname($zipfilepath, $tempdir);

        if (!$files) {

            return array();

        }

        // If requested, rename the root directory of the plugin.

        if (!empty($rootdir)) {

            $files = $this->rename_extracted_rootdir($tempdir, $rootdir, $files);

        }

        // Sometimes zip may not contain all parent directories, add them to make it consistent.

        foreach ($files as $path => $status) {

            if ($status !== true) {

                continue;

            }

            $parts = explode('/', trim($path, '/'));

            while (array_pop($parts)) {

                if (empty($parts)) {

                    break;

                }

                $dir = implode('/', $parts).'/';

                if (!isset($files[$dir])) {

                    $files[$dir] = true;

                }

            }

        }

        // Move the extracted files into the target location.

        $this->move_extracted_plugin_files($tempdir, $targetdir, $files);

        // Set the permissions of extracted subdirs and files.

        $this->set_plugin_files_permissions($targetdir, $files);

        return $files;

    }

    /**

     * Make an archive backup of the existing plugin folder.

     *

     * @param string $folderpath full path to the plugin folder

     * @param string $targetzip full path to the zip file to be created

     * @return bool true if file created, false if not

     */

    public function zip_plugin_folder($folderpath, $targetzip) {

        if (file_exists($targetzip)) {

            throw new coding_exception('Attempting to create already existing ZIP file', $targetzip);

        }

        if (!is_writable(dirname($targetzip))) {

            throw new coding_exception('Target ZIP location not writable', dirname($targetzip));

        }

        if (!is_dir($folderpath)) {

            throw new coding_exception('Attempting to ZIP non-existing source directory', $folderpath);

        }

        $files = $this->list_plugin_folder_files($folderpath);

        $fp = get_file_packer('application/zip');

        return $fp->archive_to_pathname($files, $targetzip, false);

    }

    /**

     * Archive the current plugin on-disk version.

     *

     * @param string $folderpath full path to the plugin folder

     * @param string $component

     * @param int $version

     * @param bool $overwrite overwrite existing archive if found

     * @return bool

     */

    public function archive_plugin_version($folderpath, $component, $version, $overwrite=false) {

        if ($component !== clean_param($component, PARAM_SAFEDIR)) {

            // This should never happen, but just in case.

            throw new moodle_exception('unexpected_plugin_component_format', 'core_plugin', '', null, $component);

        }

        if ((string)$version !== clean_param((string)$version, PARAM_FILE)) {

            // Prevent some nasty injections via $plugin->version tricks.

            throw new moodle_exception('unexpected_plugin_version_format', 'core_plugin', '', null, $version);

        }

        if (empty($component) or empty($version)) {

            return false;

        }

        if (!is_dir($folderpath)) {

            return false;

        }

        $archzip = $this->temproot.'/archive/'.$component.'/'.$version.'.zip';

        if (file_exists($archzip) and !$overwrite) {

            return true;

        }

        $tmpzip = make_request_directory().'/'.$version.'.zip';

        $zipped = $this->zip_plugin_folder($folderpath, $tmpzip);

        if (!$zipped) {

            return false;

        }

        // Assert that the file looks like a valid one.

        list($expectedtype, $expectedname) = core_component::normalize_component($component);

        $actualname = $this->get_plugin_zip_root_dir($tmpzip);

        if ($actualname !== $expectedname) {

            // This should not happen.

            throw new moodle_exception('unexpected_archive_structure', 'core_plugin');

        }

        make_writable_directory(dirname($archzip));

        return rename($tmpzip, $archzip);

    }

    /**

     * Return the path to the ZIP file with the archive of the given plugin version.

     *

     * @param string $component

     * @param int $version

     * @return string|bool false if not found, full path otherwise

     */

    public function get_archived_plugin_version($component, $version) {

        if (empty($component) or empty($version)) {

            return false;

        }

        $archzip = $this->temproot.'/archive/'.$component.'/'.$version.'.zip';

        if (file_exists($archzip)) {

            return $archzip;

        }

        return false;

    }

    /**

     * Returns list of all files in the given directory.

     *

     * Given a path like /full/path/to/mod/workshop, it returns array like

     *

     *  [workshop/] => /full/path/to/mod/workshop

     *  [workshop/lang/] => /full/path/to/mod/workshop/lang

     *  [workshop/lang/workshop.php] => /full/path/to/mod/workshop/lang/workshop.php

     *  ...

     *

     * Which mathes the format used by Moodle file packers.

     *

     * @param string $folderpath full path to the plugin directory

     * @return array (string)relpath => (string)fullpath

     */

    public function list_plugin_folder_files($folderpath) {

        $folder = new RecursiveDirectoryIterator($folderpath);

        $iterator = new RecursiveIteratorIterator($folder);

        $folderpathinfo = new SplFileInfo($folderpath);

        $strip = strlen($folderpathinfo->getPathInfo()->getRealPath()) + 1;

        $files = array();

        foreach ($iterator as $fileinfo) {

            if ($fileinfo->getFilename() === '..') {

                continue;

            }

            if (strpos($fileinfo->getRealPath(), $folderpathinfo->getRealPath()) !== 0) {

                throw new moodle_exception('unexpected_filepath_mismatch', 'core_plugin');

            }

            $key = substr($fileinfo->getRealPath(), $strip);

            if ($fileinfo->isDir() and substr($key, -1) !== '/') {

                $key .= '/';

            }

            $files[str_replace(DIRECTORY_SEPARATOR, '/', $key)] = str_replace(DIRECTORY_SEPARATOR, '/', $fileinfo->getRealPath());

        }

        return $files;

    }

    /**

     * Detects the plugin's name from its ZIP file.

     *

     * Plugin ZIP packages are expected to contain a single directory and the

     * directory name would become the plugin name once extracted to the Moodle

     * dirroot.

     *

     * @param string $zipfilepath full path to the ZIP files

     * @return string|bool false on error

     */

    public function get_plugin_zip_root_dir($zipfilepath) {

        $fp = get_file_packer('application/zip');

        $files = $fp->list_files($zipfilepath);

        if (empty($files)) {

            return false;

        }

        $rootdirname = null;

        foreach ($files as $file) {

            $pathnameitems = explode('/', $file->pathname);

            if (empty($pathnameitems)) {

                return false;

            }

            // Set the expected name of the root directory in the first

            // iteration of the loop.

            if ($rootdirname === null) {

                $rootdirname = $pathnameitems[0];

            }

            // Require the same root directory for all files in the ZIP

            // package.

            if ($rootdirname !== $pathnameitems[0]) {

                return false;

            }

        }

        return $rootdirname;

    }

    // This is the end, my only friend, the end ... of external public API.

    /**

     * Makes sure all temp directories exist and are writable.

     */

    protected function init_temp_directories() {

        make_writable_directory($this->temproot.'/distfiles');

        make_writable_directory($this->temproot.'/archive');

    }

    /**

     * Raise developer debugging level message.

     *

     * @param string $msg

     */

    protected function debug($msg) {

        debugging($msg, DEBUG_DEVELOPER);

    }

    /**

     * Download the ZIP file with the plugin package from the given location

     *

     * @param string $url URL to the file

     * @param string $tofile full path to where to store the downloaded file

     * @return bool false on error

     */

    protected function download_plugin_zip_file($url, $tofile) {

        if (file_exists($tofile)) {

            $this->debug('Error fetching plugin ZIP: target location exists.');

            return false;

        }

        $status = $this->download_file_content($url, $tofile);

        if (!$status) {

            $this->debug('Error fetching plugin ZIP.');

            @unlink($tofile);

            return false;

        }

        return true;

    }

    /**

     * Thin wrapper for the core's download_file_content() function.

     *

     * @param string $url URL to the file

     * @param string $tofile full path to where to store the downloaded file

     * @return bool

     */

    protected function download_file_content($url, $tofile) {

        // Prepare the parameters for the download_file_content() function.

        $headers = null;

        $postdata = null;

        $fullresponse = false;

        $timeout = 300;

        $connecttimeout = 20;

        $skipcertverify = false;

        $tofile = $tofile;

        $calctimeout = false;

        return download_file_content($url, $headers, $postdata, $fullresponse, $timeout,

            $connecttimeout, $skipcertverify, $tofile, $calctimeout);

    }

    /**

     * Renames the root directory of the extracted ZIP package.

     *

     * This internal helper method assumes that the plugin ZIP package has been

     * extracted into a temporary empty directory so the plugin folder is the

     * only folder there. The ZIP package is supposed to be validated so that

     * it contains just a single root folder.

     *

     * @param string $dirname fullpath location of the extracted ZIP package

     * @param string $rootdir the requested name of the root directory

     * @param array $files list of extracted files

     * @return array eventually amended list of extracted files

     */

    protected function rename_extracted_rootdir($dirname, $rootdir, array $files) {

        if (!is_dir($dirname)) {

            $this->debug('Unable to rename rootdir of non-existing content');

            return $files;

        }

        if (file_exists($dirname.'/'.$rootdir)) {

            // This typically means the real root dir already has the $rootdir name.

            return $files;

        }

        $found = null; // The name of the first subdirectory under the $dirname.

        foreach (scandir($dirname) as $item) {

            if (substr($item, 0, 1) === '.') {

                continue;

            }

            if (is_dir($dirname.'/'.$item)) {

                if ($found !== null and $found !== $item) {

                    // Multiple directories found.

                    throw new moodle_exception('unexpected_archive_structure', 'core_plugin');

                }

                $found = $item;

            }

        }

        if (!is_null($found)) {

            if (rename($dirname.'/'.$found, $dirname.'/'.$rootdir)) {

                $newfiles = array();

                foreach ($files as $filepath => $status) {

                    $newpath = preg_replace('~^'.preg_quote($found.'/').'~', preg_quote($rootdir.'/'), $filepath);

                    $newfiles[$newpath] = $status;

                }

                return $newfiles;

            }

        }

        return $files;

    }

    /**

     * Sets the permissions of extracted subdirs and files

     *

     * As a result of unzipping, the subdirs and files are created with

     * permissions set to $CFG->directorypermissions and $CFG->filepermissions.

     * These are too benevolent by default (777 and 666 respectively) for PHP

     * scripts and may lead to HTTP 500 errors in some environments.

     *

     * To fix this behaviour, we inherit the permissions of the plugin root

     * directory itself.

     *

     * @param string $targetdir full path to the directory the ZIP file was extracted to

     * @param array $files list of extracted files

     */

    protected function set_plugin_files_permissions($targetdir, array $files) {

        $dirpermissions = fileperms($targetdir);

        $filepermissions = ($dirpermissions & 0666);

        foreach ($files as $subpath => $notusedhere) {

            $path = $targetdir.'/'.$subpath;

            if (is_dir($path)) {

                @chmod($path, $dirpermissions);

            } else {

                @chmod($path, $filepermissions);

            }

        }

    }

    /**

     * Moves the extracted contents of the plugin ZIP into the target location.

     *

     * @param string $sourcedir full path to the directory the ZIP file was extracted to

     * @param mixed $targetdir full path to the directory where the files should be moved to

     * @param array $files list of extracted files

     */

    protected function move_extracted_plugin_files($sourcedir, $targetdir, array $files) {

        global $CFG;

        foreach ($files as $file => $status) {

            if ($status !== true) {

                throw new moodle_exception('corrupted_archive_structure', 'core_plugin', '', $file, $status);

            }

            $source = $sourcedir.'/'.$file;

            $target = $targetdir.'/'.$file;

            if (is_dir($source)) {

                continue;

            } else {

                if (!is_dir(dirname($target))) {

                    mkdir(dirname($target), $CFG->directorypermissions, true);

                }

                rename($source, $target);

            }

        }

    }

}