backup/util/checks/backup_check.class.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * @package    moodlecore
  20  * @subpackage backup-factories
  21  * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 /**
  26  * Non instantiable helper class providing different backup checks
  27  *
  28  * This class contains various static methods available in order to easily
  29  * perform a bunch of backup architecture tests
  30  *
  31  * TODO: Finish phpdocs
  32  */
  33 abstract class backup_check {
  34
  35     public static function check_format_and_type($format, $type) {
  36         global $CFG;
  37
  38         $file = $CFG->dirroot . '/backup/' . $format . '/backup_plan_builder.class.php';
  39         if (! file_exists($file)) {
  40             throw new backup_controller_exception('backup_check_unsupported_format', $format);
  41         }
  42         require_once($file);
  43         if (!in_array($type, backup_plan_builder::supported_backup_types())) {
  44             throw new backup_controller_exception('backup_check_unsupported_type', $type);
  45         }
  46
  47         require_once($CFG->dirroot . '/backup/moodle2/backup_plan_builder.class.php');
  48     }
  49
  50     public static function check_id($type, $id) {
  51         global $DB;
  52         switch ($type) {
  53             case backup::TYPE_1ACTIVITY:
  54                 // id must exist in course_modules table
  55                 if (! $DB->record_exists('course_modules', array('id' => $id))) {
  56                     throw new backup_controller_exception('backup_check_module_not_exists', $id);
  57                 }
  58                 break;
  59             case backup::TYPE_1SECTION:
  60                 // id must exist in course_sections table
  61                 if (! $DB->record_exists('course_sections', array('id' => $id))) {
  62                     throw new backup_controller_exception('backup_check_section_not_exists', $id);
  63                 }
  64                 break;
  65             case backup::TYPE_1COURSE:
  66                 // id must exist in course table
  67                 if (! $DB->record_exists('course', array('id' => $id))) {
  68                     throw new backup_controller_exception('backup_check_course_not_exists', $id);
  69                 }
  70                 break;
  71             default:
  72                 throw new backup_controller_exception('backup_check_incorrect_type', $type);
  73         }
  74         return true;
  75     }
  76
  77     public static function check_user($userid) {
  78         global $DB;
  79         // userid must exist in user table
  80         if (! $DB->record_exists('user', array('id' => $userid))) {
  81             throw new backup_controller_exception('backup_check_user_not_exists', $userid);
  82         }
  83         return true;
  84     }
  85
  86     public static function check_security($backup_controller, $apply) {
  87         global $DB;
  88
  89         if (! $backup_controller instanceof backup_controller) {
  90             throw new backup_controller_exception('backup_check_security_requires_backup_controller');
  91         }
  92         $backup_controller->log('checking plan security', backup::LOG_INFO);
  93
  94         // Some handy vars
  95         $type     = $backup_controller->get_type();
  96         $mode     = $backup_controller->get_mode();
  97         $courseid = $backup_controller->get_courseid();
  98         $coursectx= get_context_instance(CONTEXT_COURSE, $courseid);
  99         $userid   = $backup_controller->get_userid();
 100         $id       = $backup_controller->get_id(); // courseid / sectionid / cmid
 101
 102         // Note: all the checks along the function MUST be performed for $userid, that
 103         // is the user who "requested" the course backup, not current $USER at all!!
 104
 105         // First of all, decide which caps/contexts are we going to check
 106         // for common backups (general, automated...) based exclusively
 107         // in the type (course, section, activity). And store them into
 108         // one capability => context array structure
 109         $typecapstocheck = array();
 110         switch ($type) {
 111             case backup::TYPE_1COURSE :
 112                 $DB->get_record('course', array('id' => $id), '*', MUST_EXIST); // course exists
 113                 $typecapstocheck['moodle/backup:backupcourse'] = $coursectx;
 114                 break;
 115             case backup::TYPE_1SECTION :
 116                 $DB->get_record('course_sections', array('course' => $courseid, 'id' => $id), '*', MUST_EXIST); // sec exists
 117                 $typecapstocheck['moodle/backup:backupsection'] = $coursectx;
 118                 break;
 119             case backup::TYPE_1ACTIVITY :
 120                 get_coursemodule_from_id(null, $id, $courseid, false, MUST_EXIST); // cm exists
 121                 $modulectx = get_context_instance(CONTEXT_MODULE, $id);
 122                 $typecapstocheck['moodle/backup:backupactivity'] = $modulectx;
 123                 break;
 124             default :
 125                 throw new backup_controller_exception('backup_unknown_backup_type', $type);
 126         }
 127
 128         // Now, if backup mode is hub or import, check userid has permissions for those modes
 129         // other modes will perform common checks only (backupxxxx capabilities in $typecapstocheck)
 130         switch ($mode) {
 131             case backup::MODE_HUB:
 132                 if (!has_capability('moodle/backup:backuptargethub', $coursectx, $userid)) {
 133                     $a = new stdclass();
 134                     $a->userid = $userid;
 135                     $a->courseid = $courseid;
 136                     $a->capability = 'moodle/backup:backuptargethub';
 137                     throw new backup_controller_exception('backup_user_missing_capability', $a);
 138                 }
 139                 break;
 140             case backup::MODE_IMPORT:
 141                 if (!has_capability('moodle/backup:backuptargetimport', $coursectx, $userid)) {
 142                     $a = new stdclass();
 143                     $a->userid = $userid;
 144                     $a->courseid = $courseid;
 145                     $a->capability = 'moodle/backup:backuptargetimport';
 146                     throw new backup_controller_exception('backup_user_missing_capability', $a);
 147                 }
 148                 break;
 149             // Common backup (general, automated...), let's check all the $typecapstocheck
 150             // capability => context pairs
 151             default:
 152                 foreach ($typecapstocheck as $capability => $context) {
 153                     if (!has_capability($capability, $context, $userid)) {
 154                         $a = new stdclass();
 155                         $a->userid = $userid;
 156                         $a->courseid = $courseid;
 157                         $a->capability = $capability;
 158                         throw new backup_controller_exception('backup_user_missing_capability', $a);
 159                     }
 160                 }
 161         }
 162
 163         // Now, enforce 'moodle/backup:userinfo' to 'users' setting, applying changes if allowed,
 164         // else throwing exception
 165         $userssetting = $backup_controller->get_plan()->get_setting('users');
 166         $prevvalue    = $userssetting->get_value();
 167         $prevstatus   = $userssetting->get_status();
 168         $hasusercap   = has_capability('moodle/backup:userinfo', $coursectx, $userid);
 169
 170         // If setting is enabled but user lacks permission
 171         if (!$hasusercap && $prevvalue) { // If user has not the capability and setting is enabled
 172             // Now analyse if we are allowed to apply changes or must stop with exception
 173             if (!$apply) { // Cannot apply changes, throw exception
 174                 $a = new stdclass();
 175                 $a->setting = 'users';
 176                 $a->value = $prevvalue;
 177                 $a->capability = 'moodle/backup:userinfo';
 178                 throw new backup_controller_exception('backup_setting_value_wrong_for_capability', $a);
 179
 180             } else { // Can apply changes
 181                 $userssetting->set_value(false);                              // Set the value to false
 182                 $userssetting->set_status(base_setting::LOCKED_BY_PERMISSION);// Set the status to locked by perm
 183             }
 184         }
 185
 186         // Now, enforce 'moodle/backup:anonymise' to 'anonymise' setting, applying changes if allowed,
 187         // else throwing exception
 188         $anonsetting = $backup_controller->get_plan()->get_setting('anonymize');
 189         $prevvalue   = $anonsetting->get_value();
 190         $prevstatus  = $anonsetting->get_status();
 191         $hasanoncap  = has_capability('moodle/backup:anonymise', $coursectx, $userid);
 192
 193         // If setting is enabled but user lacks permission
 194         if (!$hasanoncap && $prevvalue) { // If user has not the capability and setting is enabled
 195             // Now analyse if we are allowed to apply changes or must stop with exception
 196             if (!$apply) { // Cannot apply changes, throw exception
 197                 $a = new stdclass();
 198                 $a->setting = 'anonymize';
 199                 $a->value = $prevvalue;
 200                 $a->capability = 'moodle/backup:anonymise';
 201                 throw new backup_controller_exception('backup_setting_value_wrong_for_capability', $a);
 202
 203             } else { // Can apply changes
 204                 $anonsetting->set_value(false);                              // Set the value to false
 205                 $anonsetting->set_status(base_setting::LOCKED_BY_PERMISSION);// Set the status to locked by perm
 206             }
 207         }
 208
 209         // Now, if mode is HUB or IMPORT, and still we are including users in backup, turn them off
 210         // Defaults processing should have handled this, but we need to be 100% sure
 211         if ($mode == backup::MODE_IMPORT || $mode == backup::MODE_HUB) {
 212             $userssetting = $backup_controller->get_plan()->get_setting('users');
 213             if ($userssetting->get_value()) {
 214                 $userssetting->set_value(false);                              // Set the value to false
 215                 $userssetting->set_status(base_setting::LOCKED_BY_PERMISSION);// Set the status to locked by perm
 216             }
 217         }
 218
 219         // Check the user has the ability to configure the backup. If not then we need
 220         // to lock all settings by permission so that no changes can be made.
 221         $hasconfigcap = has_capability('moodle/backup:configure', $coursectx, $userid);
 222         if (!$hasconfigcap) {
 223             $settings = $backup_controller->get_plan()->get_settings();
 224             foreach ($settings as $setting) {
 225                 if ($setting->get_name()=='filename') {
 226                     continue;
 227                 }
 228                 $setting->set_status(base_setting::LOCKED_BY_PERMISSION);
 229             }
 230         }
 231
 232         return true;
 233     }
 234 }