dms_client.module

<?php

define('DMS_VERSION', '7.x-1.0');
define('DMS_MODE_LIGHT', 'light');
define('DMS_MODE_FULL', 'full');
define('DMS_MODE_SPECIFIC', 'specific');

/**
 * Implements hook_menu().
 */
function dms_client_menu() {
  // Module status.
  $items['dms/status'] = array(
    'title' => 'DMS Status',
    'page callback' => 'dms_client_status_callback',
    'access callback' => TRUE,
  );

  // Report generation.
  $items['dms/report/generate'] = array(
    'title' => 'DMS Report Generation',
    'page callback' => 'dms_client_report_generate_callback',
    'access callback' => TRUE,
  );

  // Report generation documentation.
  $items['dms/report/describe'] = array(
    'title' => 'DMS Report Description',
    'page callback' => 'dms_client_report_describe_callback',
    'access callback' => TRUE,
  );

  // Action execution.
  $items['dms/action/%/execute'] = array(
    'title' => 'DMS Action Execution',
    'page callback' => 'dms_client_action_execute_callback',
    'page arguments' => array(2),
    'access callback' => TRUE,
  );

  // Action execution documentation.
  $items['dms/action/describe'] = array(
    'title' => 'DMS Action Execution Description',
    'page callback' => 'dms_client_action_describe_callback',
    'access callback' => TRUE,
  );

  // Special path to allow download of private files.
  $items['dms/download/%'] = array(
    'title' => 'DMS Download Execution',
    'page callback' => 'dms_client_download_callback',
    'page arguments' => array(2),
    'access callback' => TRUE,
  );

  // Module settings.
  $items['admin/config/system/dms_client/settings'] = array(
    'title' => 'DMS Client Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('dms_client_settings_form'),
    'file' => 'dms_client.inc',
    'access callback' => TRUE,
  );

  return $items;
}

/**
 * Check access to the DMS client APIs.
 */
function dms_client_access_callback() {
  if(!dms_client_valid_request()) {
    dms_client_send_json(array(
      'code' => 403,
      'error' => 'Not allowed to access the DMS API.'
    ));
  }
}

/**
 * Unprotected menu callback to check if
 * module is well configured and working.
 *
 * @return string
 *   The JSON data.
 */
function dms_client_status_callback() {
  // Check if the module is well configured.
  $working = dms_client_valid_request();
  if ($working) {
    $response = array(
      'code' => 200,
      'data' => array(
        'message' => 'DMS is working properly.',
        'version' => DMS_VERSION
      )
    );
  } else {
    drupal_add_http_header('Status', '403 Not Allowed');
    $response = array(
      'code' => 403,
      'data' => array(
        'message' => 'Access not allowed. Please, check access token and allowed IPs.',
        'version' => DMS_VERSION
      )
    );
  }

  // Return JSON data.
  dms_client_send_json($response);
}

/**
 * Menu callback for describing report available data.
 *
 * @return string
 *   The JSON string of data.
 */
function dms_client_report_describe_callback() {
  // Check access before doing anything.
  dms_client_access_callback();

  // Get request parameters.
  $response = array('code' => 200, 'data' => array());

  // Display all modes information.
  $modes = dms_client_report_modes();
  foreach ($modes as $mode => $text) {
    $response['data']['modes'][$mode] = $text;
  }

  // Display all tasks information.
  $tasks = dms_client_report_tasks();
  foreach ($tasks as $task => $task_data) {
    $response['data']['tasks'][$task] = $task_data;
  }

  // Return JSON data.
  dms_client_send_json($response);
}

/**
 * Menu callback for describing available actions.
 *
 * @return string
 *   The JSON string of data.
 */
function dms_client_action_describe_callback() {
  // Check access before doing anything.
  dms_client_access_callback();

  // Get request parameters.
  $response = array('code' => 200, 'data' => array());

  // Display all modes information.
  $actions = dms_client_actions();
  foreach ($actions as $action => $action_data) {
    $response['data']['actions'][$action] = $action_data;
  }

  // Return JSON data.
  dms_client_send_json($response);
}

/**
 * Menu callback for generating a report.
 *
 * @return string
 *   The JSON string of data.
 */
function dms_client_report_generate_callback() {
  // Check access before doing anything.
  dms_client_access_callback();

  // Get request parameters.
  $response = array('code' => 200, 'data' => array());
  $mode = dms_get_mode_from_request();
  $checklist = dms_get_checklist_from_request($mode);

  // Execute each tasks.
  foreach ($checklist as $key => $task) {
    if (function_exists($task['callback'])) {
      try {
        // Execute the callback.
        $start = microtime(true);
        $response['data'][$key]['result'] = $task['callback']();
        $total = microtime(true) - $start;
        $response['data'][$key]['time'] = $total;
        $response['data'][$key]['code'] = 200;

      } catch (\Exception $e) {
        // Internal error response code.
        $response['data'][$key]['code'] = 500;
        $response['data'][$key]['error'] = 'DMS Client : ' . $e->getMessage();
      }
    }
  }

  // Let other modules alter the response.
  drupal_alter('dms_client_report', $response['data']);

  // Return JSON data.
  dms_client_send_json($response);
}

/**
 * Menu callback for action execution.
 *
 * @param string $key
 *   An action key to execute.
 *
 * @return string
 *   The JSON data.
 */
function dms_client_action_execute_callback($key) {
  // Check access before doing anything.
  dms_client_access_callback();

  // Get request parameters.
  $response = array('code' => 200, 'data' => array());

  // Execute the action.
  $actions = dms_client_actions();
  foreach ($actions as $action_key => $action) {
    if ($action_key == $key) {
      if (function_exists($action['callback'])) {
        try {
          // Execute the action.
          $start = microtime(true);
          $response['data'][$action_key]['result'] = $action['callback']();
          $total = microtime(true) - $start;
          $response['data'][$action_key]['time'] = $total;
          $response['data'][$action_key]['code'] = 200;

        } catch (\Exception $e) {
          // Internal error response code.
          $response['data'][$action_key]['code'] = 500;
          $response['data'][$action_key]['error'] = 'DMS Client : ' . $e->getMessage();
        }
      }
    }
  }

  // Let other modules alter the response.
  drupal_alter('dms_client_report', $response['data']);

  // Return JSON data.
  dms_client_send_json($response);
}

/**
 * Menu callback for downloads.
 *
 * @param string $path
 *   A path to a file to download, encoded in base64.
 */
function dms_client_download_callback($path) {
  // Check access before doing anything.
  dms_client_access_callback();

  // Decode the path.
  $path = base64_decode($path);

  // Check if file exists and is allowed.
  if (!file_exists($path) || !dms_client_download_allowed($path)) {
    drupal_not_found();
  }

  // Send HTTP headers.
  $file = pathinfo($path);
  drupal_add_http_header('Content-Type', 'application/octet-stream');
  drupal_add_http_header('Content-Length', filesize($path));
  drupal_add_http_header('Content-Disposition', 'attachment; filename="' . $file['basename'] . '"');
  drupal_send_headers();

  // Transfer file in 1024 byte chunks to save memory usage.
  if ($fd = fopen($path, 'rb')) {
    while (!feof($fd)) {
      print fread($fd, 1024);
    }
    fclose($fd);
  }

  drupal_exit();
}

/**
 * Check if a download is allowed.
 *
 * @param string $path
 *   A path to a file to download.
 *
 * @return boolean
 *   True if allowed, False otherwise.
 */
function dms_client_download_allowed($path) {
  $allowed = array(
    drupal_get_path('module', 'dms_client') . '/dumps/database.gz'
  );

  // Let other modules alter the list of allowed files.
  drupal_alter('dms_client_report_modes', $allowed, $path);

  return in_array($path, $allowed);
}

/**
 * Return the URL to a downloadable file.
 *
 * @param string $path
 *   A path to a file to download.
 *
 * @return string|FALSE
 *   The URL to access the file, False if not allowed.
 */
function dms_client_download_get_url($path) {
  if (!dms_client_download_allowed($path)) {
    return FALSE;
  }

  // Return the generated URL.
  return url('dms/download/' . base64_encode($path), array('query' => drupal_get_query_parameters(), 'absolute' => TRUE));
}

/**
 * Get the mode to use from request.
 *
 * @return string
 *   The mode to use : light, full, specific.
 */
function dms_get_mode_from_request() {
  // Get request parameters.
  $params = drupal_get_query_parameters();

  // Available modes (default: 'light')
  $modes = dms_client_report_modes();
  $mode = 'light';
  if (array_key_exists('mode', $params) && array_key_exists($params['mode'], $modes)) {
    $mode = $params['mode'];
  }

  // If specifics are asked, auto change mode.
  if (array_key_exists('specifics', $params)) {
    $mode = 'specific';
  }

  return $mode;
}

/**
 * Get the specific tasks to do from request.
 *
 * @return array
 *   A list of tasks keys.
 */
function dms_get_specifics_from_request() {
  $keys = array();

  $params = drupal_get_query_parameters();
  if (isset($params['specifics']) && !empty($params['specifics'])) {
    if (is_array($params['specifics'])) {
      $keys = $params['specifics'];
    } elseif (strpos($params['specifics'], ',') !== FALSE) {
      $keys = explode(',', $params['specifics']);
    } else {
      $keys = array($params['specifics']);
    }
  }

  return $keys;
}

/**
 * Get the checklist of tasks to do from the request.
 *
 * @param string $mode
 *   The mode to use.
 *
 * @return array
 *   The array of checklist of tasks.
 */
function dms_get_checklist_from_request($mode) {
  $tasks = array();

  $specifics = dms_get_specifics_from_request();
  $all_tasks = dms_client_report_tasks();

  // Filter by mode/specifics.
  foreach ($all_tasks as $key => $task) {
    if ($mode !== DMS_MODE_SPECIFIC && in_array($mode, $task['modes'])) {
      // If task is enabled for given mode.
      $tasks[$key] = $task;

    } elseif ($mode === DMS_MODE_SPECIFIC && in_array($key, $specifics)) {
      // If task is explicitly asked.
      $tasks[$key] = $task;
    }
  }

  return $tasks;
}

/**
 * Return all defined modes for generating reports.
 *
 * @return array
 *   An array of modes.
 */
function dms_client_report_modes() {
  $modes = array(
    DMS_MODE_FULL => 'Full mode, all main tasks.',
    DMS_MODE_LIGHT => 'Light mode, only a few tasks.',
    DMS_MODE_SPECIFIC => 'Specific mode, you can choose which tasks to execute via the "specifics" query parameter.'
  );

  // Let other modules alter the list of modes.
  drupal_alter('dms_client_report_modes', $modes);

  return $modes;
}

/**
 * Return all defined tasks for generating reports.
 *
 * @return array
 *   An array of tasks.
 */
function dms_client_report_tasks() {
  $tasks = array(
    'system_status' => array(
      'modes' => array(DMS_MODE_FULL, DMS_MODE_LIGHT),
      'callback' => 'dms_client_system_status'
    ),
    'updates' => array(
      'modes' => array(DMS_MODE_FULL),
      'callback' => 'dms_client_updates_status'
    ),
    'features' => array(
      'modes' => array(DMS_MODE_FULL),
      'callback' => 'dms_client_features_status'
    ),
    'statistics' => array(
      'modes' => array(DMS_MODE_FULL),
      'callback' => 'dms_client_statistics'
    ),
    'hack' => array(
      'modes' => array(DMS_MODE_FULL),
      'callback' => 'dms_client_hack_check'
    ),
    'logs' => array(
      'modes' => array(DMS_MODE_FULL),
      'callback' => 'dms_client_logs_check'
    ),
    'server' => array(
      'modes' => array(DMS_MODE_FULL),
      'callback' => 'dms_client_server_check'
    ),
  );

  // Let other modules alter the list of tasks.
  drupal_alter('dms_client_report_tasks', $tasks);

  return $tasks;
}

/**
 * Return all defined actions.
 *
 * @return array
 *   An array of actions.
 */
function dms_client_actions() {
  $actions = array(
    'uli' => array(
      'callback' => 'dms_client_action_uli',
      'description' => 'Login the user as administrator.',
      'title' => 'Login'
    ),
    'cron_run' => array(
      'callback' => 'dms_client_action_cron',
      'description' => 'Run the Drupal CRON.',
      'title' => 'Run CRON'
    ),
    'cache_clear' => array(
      'callback' => 'dms_client_action_cache_clear',
      'description' => 'Clear all Drupal caches.',
      'title' => 'Clear cache'
    ),
    'dump_db' => array(
      'callback' => 'dms_client_action_dump_db',
      'description' => 'Dump the website database.',
      'title' => 'Dump DB'
    ),
  );

  // Let other modules alter the list of actions.
  drupal_alter('dms_client_actions', $actions);

  return $actions;
}

/**
 * Check the access token for current request.
 *
 * @return bool
 *   True if access is granted, False otherwise.
 */
function dms_client_valid_request() {
  // Check token is here.
  $params = drupal_get_query_parameters();
  if (!array_key_exists('secret', $params)) {
    return FALSE;
  }

  // Check tokens & IP.
  $server_token = $params['secret'];
  $client_token = dms_client_get_token();
  $current_ip = ip_address();

  return ($server_token == $client_token) && dms_client_check_ip($current_ip);
}

/**
 * Get the current client token.
 *
 * @return string
 *   The token.
 */
function dms_client_get_token() {
  return variable_get('dms_client_secret', dms_client_generate_token());
}

/**
 * Check the current request IP is allowed.
 *
 * @param string $ip
 *   The IP to check.
 *
 * @return boolean
 *   True if IP is allowed, False otherwise.
 */
function dms_client_check_ip($ip) {
  // Bypass if developer mode.
  if (variable_get('dms_client_dev_mode', FALSE)) {
    return TRUE;
  }

  // Check if IP is allowed.
  $allowed = variable_get('dms_client_allowed_ips', '');
  if (strlen($allowed) > 0) {
    $allowed = explode("\n", str_replace("\r", '', $allowed));
    return in_array($ip, $allowed);
  }

  return FALSE;
}

/**
 * Helper to send JSON data.
 *
 * @param array $data
 */
function dms_client_send_json(array $data) {
  drupal_add_http_header('Content-Type', 'application/json');
  drupal_add_http_header('Access-Control-Allow-Origin', "*");
  drupal_add_http_header('Access-Control-Allow-Methods', 'GET,POST');
  echo json_encode($data);
  exit;
}

/**
 * Generates a random token.
 *
 * @param $length
 *   The length of the generated token.
 *
 * @return string
 *   The random string.
 */
function dms_client_generate_token($length = 255) {
  $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
  $randomString = '';
  for ($i = 0; $i < $length; $i++) {
    $randomString .= $characters[rand(0, strlen($characters) - 1)];
  }
  return $randomString;
}

/** * * * * * * * * *
 * TASKS CALLBACKS. *
 * * * * * * * * * **/

/**
 * System status.
 *
 * @see see modules/system/system.admin.inc
 *
 * @return array
 */
function dms_client_system_status() {
  // Load .install files
  include_once DRUPAL_ROOT . '/includes/install.inc';
  drupal_load_updates();

  // Check run-time requirements and status information.
  $requirements = module_invoke_all('requirements', 'runtime');
  usort($requirements, '_system_sort_requirements');

  return $requirements;
}

/**
 * Updates status.
 *
 * @see modules/update/update.manager.inc
 * @return array
 * @throws \Exception
 */
function dms_client_updates_status() {
  module_load_include('module', 'update', 'update');
  $available = update_get_available(TRUE);
  if (empty($available)) {
    throw new \Exception('There was a problem getting update information. Try again later.');
  }

  // This will be a nested array. The first key is the kind of project, which
  // can be either 'enabled', 'disabled', 'manual' (projects which require
  // manual updates, such as core). Then, each subarray is an array of
  // projects of that type, indexed by project short name, and containing an
  // array of data for cells in that project's row in the appropriate table.
  $projects = array();

  module_load_include('inc', 'update', 'update.compare');
  $project_data = update_calculate_project_data($available);

  foreach ($project_data as $name => $project) {
    // Filter out projects which are up to date already.
    if ($project['status'] == UPDATE_CURRENT) {
      continue;
    }
    // The project name to display can vary based on the info we have.
    if (!empty($project['title'])) {
      if (!empty($project['link'])) {
        $project_name = l($project['title'], $project['link']);
      }
      else {
        $project_name = check_plain($project['title']);
      }
    }
    elseif (!empty($project['info']['name'])) {
      $project_name = check_plain($project['info']['name']);
    }
    else {
      $project_name = check_plain($name);
    }
    if ($project['project_type'] == 'theme' || $project['project_type'] == 'theme-disabled') {
      $project_name .= ' ' . t('(Theme)');
    }

    if (empty($project['recommended'])) {
      // If we don't know what to recommend they upgrade to, we should skip
      // the project entirely.
      continue;
    }

    $recommended_release = $project['releases'][$project['recommended']];
    $recommended_version = $recommended_release['version'] . ' ' . l(t('(Release notes)'), $recommended_release['release_link'], array('attributes' => array('title' => t('Release notes for @project_title', array('@project_title' => $project['title'])))));
    if ($recommended_release['version_major'] != $project['existing_major']) {
      $recommended_version .= '<div title="Major upgrade warning" class="update-major-version-warning">' . t('This update is a major version update which means that it may not be backwards compatible with your currently running version.  It is recommended that you read the release notes and proceed at your own risk.') . '</div>';
    }

    // Create an entry for this project.
    $entry = array(
      'title' => $project_name,
      'installed_version' => $project['existing_version'],
      'recommended_version' => $recommended_version,
    );

    switch ($project['status']) {
      case UPDATE_NOT_SECURE:
      case UPDATE_REVOKED:
        $entry['title'] .= ' ' . t('(Security update)');
        $type = 'security';
        break;

      case UPDATE_NOT_SUPPORTED:
        $type = 'unsupported';
        $entry['title'] .= ' ' . t('(Unsupported)');
        break;

      case UPDATE_UNKNOWN:
      case UPDATE_NOT_FETCHED:
      case UPDATE_NOT_CHECKED:
      case UPDATE_NOT_CURRENT:
        $type = 'recommended';
        break;

      default:
        // Jump out of the switch and onto the next project in foreach.
        continue 2;
    }
    if ($name != 'drupal') {
      $projects[$type][$name] = $entry;
    }
    else {
      $entry['type'] = $type;
      $projects[$name] = $entry;
    }
  }

  if (empty($projects)) {
    return array('uptodate' => t('All of your projects are up to date.'));
  }
  return $projects;
}

/**
 * Features status.
 *
 * @see features/features.admin.inc
 * @return array
 * @throws \Exception
 */
function dms_client_features_status() {
  if (!module_exists('features')) {
    throw new \Exception('The features module is not enabled.');
  }

  module_load_include('inc', 'features', 'features.export');

  // Sort the Features list before compiling the output.
  $features = features_get_features();
  ksort($features);

  foreach ($features as $k => $m) {
    $storage = $feature_key = NULL;
    switch (features_get_storage($m->name)) {
      case FEATURES_DEFAULT:
        $feature_key = 'default';
        $storage = '';
        break;
      case FEATURES_REBUILDABLE:
        $feature_key = 'rebuildable';
        $storage = '';
        break;
      case FEATURES_OVERRIDDEN:
        $feature_key = 'overridden';
        $storage = 'Overridden';
        break;
      case FEATURES_NEEDS_REVIEW:
        $feature_key = 'need_review';
        $storage = 'Need review';
        break;
    }
    if ($m->status) {
      $rows['enabled'][$feature_key][$m->name] = array(
        'name' => $m->info['name'],
        'version' => $m->info['version'],
        'storage' => $storage
      );
    }
    else {
      $rows['disabled'][$m->name] = array(
        'name' => $m->info['name'],
        'version' => $m->info['version'],
        'storage' => $storage
      );
    }
  }

  if (empty($rows)) {
    return array('nofeatures' => t('No Features were found.'));
  }
  return $rows;
}

/**
 * Statistics.
 * For example, users count, nodes count, lang, etc.
 *
 * @return array
 */
function dms_client_statistics() {
  // Languages.
  $languages = language_list('enabled');
  $statistics['language'] = array(
    'list' => array_shift($languages),
    'default' => language_default()
  );

  // Users count.
  $statistics['users'] = db_select('users', 'u')
    ->countQuery()
    ->execute()
    ->fetchField();

  // Nodes count.
  $statistics['nodes']['published'] = db_select('node', 'n')
    ->condition('n.status', 1)
    ->countQuery()
    ->execute()
    ->fetchField();
  $statistics['nodes']['unpublished'] = db_select('node', 'n')
    ->condition('n.status', 0)
    ->countQuery()
    ->execute()
    ->fetchField();

  return $statistics;
}

/**
 * Check if modules are hacked with MD5check.
 *
 * @return array
 * @throws \Exception
 */
function dms_client_hack_check() {
  if (!module_exists('md5check')) {
    throw new \Exception('The md5check module is not enabled.');
  }

  $hacked = array();
  // Fetches an array of all active modules and looping through them
  $modules = module_list(TRUE, FALSE);
  foreach ($modules as $moduleName) {
    $modulePath = drupal_get_path('module', $moduleName);

    // Don't check customs
    if (strpos($modulePath, 'modules/features') === FALSE && strpos($modulePath, 'modules/custom') === FALSE) {
      // Loads the module data from database
      $module = md5check_get_values_for_module($moduleName);
      // Creates a md5 hash of the modules files
      $md5 = md5check_calculate_md5_value_for_module($module);

      // If the existing module md5 hash isn't null (as never runned before) we'll check if it has changed
      // else we'll just store the new value
      if ($module->md5check !== NULL) {
        if ($md5 != $module->md5check) {
          // The value has changed as in a files content has changed - we'll report this
          $hacked[] = $moduleName;
        }
      }
      else {
        // Existing value is null - new value will be stored
        md5check_setMD5value($module->filename, $md5);
      }
    }
  }

  return $hacked;
}

/**
 * Logs status (daily counter by severity).
 *
 * @TODO check if dblog disabled.
 *
 * @return array
 */
function dms_client_logs_check() {
  $logs = array();
  $logs_status = array(
    'danger'  => array(WATCHDOG_ALERT, WATCHDOG_CRITICAL, WATCHDOG_EMERGENCY),
    'warning' => array(WATCHDOG_ERROR, WATCHDOG_WARNING),
    'info'    => array(WATCHDOG_NOTICE, WATCHDOG_DEBUG, WATCHDOG_INFO)
  );

  $thisMorning = strtotime('today midnight');

  foreach ($logs_status as $status => $severities) {
    $query = db_select('watchdog', 'w')
      ->condition('w.timestamp', $thisMorning, '>')
      ->condition('w.severity', $severities, 'IN')
      ->fields('w', array('wid'));

    $logs[$status] = $query->countQuery()->execute()->fetchField();
  }
  
  return $logs;
}

/**
 * Server information.
 *
 * @see scripts/serverinfo.sh
 * @return array
 * @throws \Exception
 */
function dms_client_server_check() {
  $path = drupal_get_path('module', 'dms_client') . '/scripts/serverinfo.sh';
  if (file_exists($path) && is_readable($path)) {
    $output = '';

    // Execute the script.
    exec($path, $output);
    if (is_array($output)) {
      $output = array_shift($output);
    }

    // Check that output is not null.
    if (is_null($output) || strlen($output) == 0) {
      throw new \Exception('Check that your script located at ' . $path . ' is executable.');
    }

    // Decode the JSON.
    $server = json_decode($output);
    if (is_null($server)) {
      $message = function_exists('json_last_error_msg') ? json_last_error_msg() : json_last_error();
      throw new \Exception('JSON parse error : ' . $message);
    }
  } else {
    throw new \Exception('Check that your script located at ' . $path . ' is readable.');
  }

  return $server;
}

/** * * * * * * * * * *
 * ACTIONS CALLBACKS. *
 * * * * * * * * * * **/

/**
 * Action: login a user.
 *
 * @return array
 * @throws \Exception
 */
function dms_client_action_uli() {
  $admin = user_load(1);
  if (!$admin) {
    throw new \Exception('No admin user found.');
  }

  return array('message' => '<a href="' . url(user_pass_reset_url($admin) . '/login').'">Click to login as an administrator</a>');
}

/**
 * Action: run the cron.
 *
 * @return array
 * @throws \Exception
 */
function dms_client_action_cron() {
  if (!drupal_cron_run()) {
    throw new \Exception('Cron run failed.');
  }

  return array('message' => 'Cron was executed successfully');
}

/**
 * Action: clear all caches.
 *
 * @return array
 */
function dms_client_action_cache_clear() {
  drupal_flush_all_caches();
  return array('message' => 'All caches were flushed successfully');
}

/**
 * Action: dump database.
 *
 * @return array
 * @throws \Exception
 */
function dms_client_action_dump_db() {
  global $databases;

  // Increase the maximum execution time.
  if (!ini_get('safe_mode') && strpos(ini_get('disable_functions'), 'set_time_limit') === FALSE && ini_get('max_execution_time') < 1200) {
    set_time_limit(1200);
  }

  // Set paths.
  $dump_path = drupal_get_path('module', 'dms_client') . '/dumps/database.gz';
  if (file_exists($dump_path)) unlink($dump_path);

  // Use the default database.
  $default_db = $databases['default']['default'];

  // Dump the database.
  exec('mysqldump -p' . $default_db['password'] . ' --user=' . $default_db['username'] . ' --host=' . $default_db['host'] . ' --compact ' . $default_db['database'] . ' | gzip > ' . $dump_path);

  // Prepare and send back the download link.
  $url = dms_client_download_get_url($dump_path);
  if ($url === FALSE) {
    throw new \Exception('URL to download the dump can not be generated.');
  }

  return array('message' => '<a href="' . $url . '">Click to download database dump</a>');
}