class DefaultMailSystem in Drupal 7

The default Drupal mail backend using PHP's mail function.

Hierarchy

• class \DefaultMailSystem implements MailSystemInterface

1 string reference to 'DefaultMailSystem'

drupal_mail_system in includes/mail.inc

Returns an object that implements the MailSystemInterface interface.

File

modules/system/system.mail.inc, line 11

Drupal core implementations of MailSystemInterface.

class DefaultMailSystem implements MailSystemInterface {

  /**
   * Concatenate and wrap the e-mail body for plain-text mails.
   *
   * @param $message
   *   A message array, as described in hook_mail_alter().
   *
   * @return
   *   The formatted $message.
   */
  public function format(array $message) {

    // Join the body array into one string.
    $message['body'] = implode("\n\n", $message['body']);

    // Convert any HTML to plain-text.
    $message['body'] = drupal_html_to_text($message['body']);

    // Wrap the mail body for sending.
    $message['body'] = drupal_wrap_mail($message['body']);
    return $message;
  }

  /**
   * Send an e-mail message, using Drupal variables and default settings.
   *
   * @see http://php.net/manual/function.mail.php
   * @see drupal_mail()
   *
   * @param $message
   *   A message array, as described in hook_mail_alter().
   * @return
   *   TRUE if the mail was successfully accepted, otherwise FALSE.
   */
  public function mail(array $message) {

    // If 'Return-Path' isn't already set in php.ini, we pass it separately
    // as an additional parameter instead of in the header.
    // However, if PHP's 'safe_mode' is on, this is not allowed.
    if (isset($message['headers']['Return-Path']) && !ini_get('safe_mode')) {
      $return_path_set = strpos(ini_get('sendmail_path'), ' -f');
      if (!$return_path_set) {
        $message['Return-Path'] = $message['headers']['Return-Path'];
        unset($message['headers']['Return-Path']);
      }
    }
    $mimeheaders = array();
    foreach ($message['headers'] as $name => $value) {
      $mimeheaders[] = $name . ': ' . mime_header_encode($value);
    }
    $line_endings = variable_get('mail_line_endings', MAIL_LINE_ENDINGS);

    // Prepare mail commands.
    $mail_subject = mime_header_encode($message['subject']);

    // Note: e-mail uses CRLF for line-endings. PHP's API requires LF
    // on Unix and CRLF on Windows. Drupal automatically guesses the
    // line-ending format appropriate for your system. If you need to
    // override this, adjust $conf['mail_line_endings'] in settings.php.
    $mail_body = preg_replace('@\\r?\\n@', $line_endings, $message['body']);

    // For headers, PHP's API suggests that we use CRLF normally,
    // but some MTAs incorrectly replace LF with CRLF. See #234403.
    $mail_headers = join("\n", $mimeheaders);

    // We suppress warnings and notices from mail() because of issues on some
    // hosts. The return value of this method will still indicate whether mail
    // was sent successfully.
    if (!isset($_SERVER['WINDIR']) && strpos($_SERVER['SERVER_SOFTWARE'], 'Win32') === FALSE) {

      // We validate the return path, unless it is equal to the site mail, which
      // we assume to be safe.
      if (isset($message['Return-Path']) && !ini_get('safe_mode') && (variable_get('site_mail', ini_get('sendmail_from')) === $message['Return-Path'] || self::_isShellSafe($message['Return-Path']))) {

        // On most non-Windows systems, the "-f" option to the sendmail command
        // is used to set the Return-Path. There is no space between -f and
        // the value of the return path.
        $mail_result = @mail($message['to'], $mail_subject, $mail_body, $mail_headers, '-f' . $message['Return-Path']);
      }
      else {

        // The optional $additional_parameters argument to mail() is not
        // allowed if safe_mode is enabled. Passing any value throws a PHP
        // warning and makes mail() return FALSE.
        $mail_result = @mail($message['to'], $mail_subject, $mail_body, $mail_headers);
      }
    }
    else {

      // On Windows, PHP will use the value of sendmail_from for the
      // Return-Path header.
      $old_from = ini_get('sendmail_from');
      ini_set('sendmail_from', $message['Return-Path']);
      $mail_result = @mail($message['to'], $mail_subject, $mail_body, $mail_headers);
      ini_set('sendmail_from', $old_from);
    }
    return $mail_result;
  }

  /**
   * Disallows potentially unsafe shell characters.
   *
   * Functionally similar to PHPMailer::isShellSafe() which resulted from
   * CVE-2016-10045. Note that escapeshellarg and escapeshellcmd are inadequate
   * for this purpose.
   *
   * @param string $string
   *   The string to be validated.
   *
   * @return bool
   *   True if the string is shell-safe.
   *
   * @see https://github.com/PHPMailer/PHPMailer/issues/924
   * @see https://github.com/PHPMailer/PHPMailer/blob/v5.2.21/class.phpmailer.php#L1430
   *
   * @todo Rename to ::isShellSafe() and/or discuss whether this is the correct
   *   location for this helper.
   */
  protected static function _isShellSafe($string) {
    if (escapeshellcmd($string) !== $string || !in_array(escapeshellarg($string), array(
      "'{$string}'",
      "\"{$string}\"",
    ))) {
      return FALSE;
    }
    if (preg_match('/[^a-zA-Z0-9@_\\-.]/', $string) !== 0) {
      return FALSE;
    }
    return TRUE;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DefaultMailSystem::format	public	function	Concatenate and wrap the e-mail body for plain-text mails. Overrides MailSystemInterface::format
DefaultMailSystem::mail	public	function	Send an e-mail message, using Drupal variables and default settings. Overrides MailSystemInterface::mail	1
DefaultMailSystem::_isShellSafe	protected static	function	Disallows potentially unsafe shell characters.