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/>.

namespace core\task;

use core\http_client;

use moodle_exception;

use PharData;

/**

 * Simple task to update the GeoIP database file.

 *

 * @package     core

 * @author      Trisha Milan <trishamilan@catalyst-au.net>

 * @copyright   Monash University 2024

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

 */

class update_geoip2file_task extends scheduled_task {

    /**

     * Get a descriptive name for this task (shown to admins).

     *

     * @return string

     */

    public function get_name(): string {

        return get_string('taskupdategeoip2file', 'admin');

    }

    /**

     * Execute the task to update the GeoIP2 database file.

     *

     * @throws \GuzzleHttp\Exception\GuzzleException

     * @throws moodle_exception

     */

    public function execute(): void {

        global $CFG;

        if (!$CFG->geoipmaxmindaccid || !$CFG->geoipmaxmindlicensekey) {

            mtrace("MaxMind account information is incomplete. Please configure the account ID and license key.");

            return;

        }

        // Setup base directory path and permissions.

        $geoip2file = $CFG->geoip2file;

        $geoipdirectory = dirname($geoip2file);

        if (!check_dir_exists($geoipdirectory) && !mkdir($geoipdirectory, $CFG->directorypermissions, true)) {

            throw new moodle_exception("Cannot create output directory $geoipdirectory");

        }

        $geoippermalink = 'https://download.maxmind.com/geoip/databases/' . $CFG->geoipdbedition . '/download';

        $client = new http_client(['auth' => [$CFG->geoipmaxmindaccid, $CFG->geoipmaxmindlicensekey]]);

        $response = $client->head($geoippermalink, ['query' => ['suffix' => 'tar.gz']]);

        $headers = $response->getHeaders();

        $lastmodified = strtotime($headers['Last-Modified'][0]);

        if (!$this->is_update_needed($geoip2file, $lastmodified)) {

            mtrace("No update needed. The GeoIP database is up to date.");

            return;

        }

        // Define path for downloading the GeoIP2 archive.

        $archivefilename = 'GeoIP-City.tar.gz';

        $tempdirectory = make_request_directory(true);

        $geoipdownloadpath = $tempdirectory . '/' . $archivefilename;

        mtrace("Downloading $CFG->geoipdbedition database from MaxMind......");

        $response = $client->request('GET', $geoippermalink, [

            'query' => ['suffix' => 'tar.gz'],

            'sink' => $geoipdownloadpath,

        ]);

        if ($response->getStatusCode() != 200) {

            throw new moodle_exception("Error downloading file.");

        }

        mtrace("File downloaded successfully to $geoipdownloadpath");

        mtrace("Verifying checksum......");

        // Get the latest checksum from MaxMind.

        $checksumcontent = $client->get($geoippermalink, ['query' => ['suffix' => 'tar.gz.sha256']])->getBody()->getContents();

        list($checksum) = explode(' ', $checksumcontent);

        if (!$this->verify_checksum($checksum, $geoipdownloadpath)) {

            throw new moodle_exception("Checksum verification failed.");

        }

        mtrace("Checksum verified successfully.");

        if ($this->update_geoip2file($geoipdownloadpath, $tempdirectory, $geoip2file)) {

            // Store the last seen timestamp.

            set_config('geoip_last_seen_timestamp', $lastmodified);

            mtrace("GeoIP database update successful!");

        } else {

            throw new moodle_exception("GeoIP database update failed.");

        }

    }

    /**

     * Determines if an update is needed for the GeoIP2 file based on the last modified date.

     *

     * @param string $geoip2file The path to the GeoIP2 file that needs to be checked for updates.

     * @param string $lastmodified The last modified date to be compared against the stored last seen timestamp.

     * @return bool

     */

    private function is_update_needed(string $geoip2file, string $lastmodified): bool {

        return !file_exists($geoip2file) || $lastmodified !== get_config('core', 'geoip_last_seen_timestamp');

    }

    /**

     * Verify the checksum of the downloaded file against an expected checksum.

     *

     * @param string $expectedchecksum The checksum expected for the file.

     * @param string $geoipdownloadpath The path where the downloaded geoip archive is located.

     * @return bool Returns true if the checksums match, returns false otherwise.

     */

    private function verify_checksum(string $expectedchecksum, string $geoipdownloadpath): bool {

        $actualchecksum = hash_file('sha256', $geoipdownloadpath);

        return $expectedchecksum === $actualchecksum;

    }

    /**

     * Extract the archive and update the GeoIP2 database file.

     *

     * @param string $archivepath The path to the archive file that needs to be extracted.

     * @param string $targetdirectory Directory where the archive contents will be extracted.

     * @param string $geoip2file The path to move the extracted GeoIP2 file.

     * @return bool Returns true if the file was successfully extracted and moved to the specified location,

     *              false if any part of the process fails.

     */

    private function update_geoip2file(string $archivepath, string $targetdirectory, string $geoip2file): bool {

        $archive = new PharData($archivepath);

        $archivename = $archive->getFilename();

        mtrace("Extracting file......");

        $archive->extractTo($targetdirectory);

        $sourcefolder = $targetdirectory . '/' . $archivename;

        // Find the mmdb file.

        $mmdbfiles = glob($sourcefolder . '/*.mmdb');

        if (count($mmdbfiles) > 1) {

            throw new moodle_exception("Multiple .mmdb files found in the extracted folder.");

        } else if (count($mmdbfiles) === 0) {

            throw new moodle_exception("GeoIP file does not exist.");

        }

        // Backup existing GeoIP file before attempting to update.

        $geoip2filename = basename($geoip2file);

        $backuppath = $targetdirectory . '/' . 'backup_' . $geoip2filename;

        if (file_exists($geoip2file)) {

            if (!rename($geoip2file, $backuppath)) {

                mtrace("Failed to create a backup of the existing GeoIP database.");

            }

            mtrace("Temporary backup of existing GeoIP file has been created.");

        }

        mtrace("Moving {$mmdbfiles[0]} into $geoip2file");

        if (!copy($mmdbfiles[0], $geoip2file)) {

            mtrace("Failed to update $geoip2filename.");

            // Attempt to restore the original file from the backup.

            if (file_exists($backuppath)) {

                mtrace("Attempting to restore from backup.");

                if (!copy($backuppath, $geoip2file)) {

                    throw new moodle_exception("Failed to restore the GeoIP database from backup.");

                } else {

                    mtrace("The GeoIP database has been restored from the backup successfully.");

                }

            }

            return false;

        }

        mtrace("$geoip2filename updated successfully.");

        return true;

    }

}