resolve($name, $typeRestriction, $cancellation); } /** * @throws DnsException *@see DnsResolver::query() * */ function query(string $name, int $type, ?Cancellation $cancellation = null): array { return dnsResolver()->query($name, $type, $cancellation); } /** * Checks whether a string is a valid DNS name. * * @param string $name String to check. */ function isValidName(string $name): bool { try { normalizeName($name); return true; } catch (InvalidNameException) { return false; } } /** * Normalizes a DNS name and automatically checks it for validity. * * @param string $name DNS name. * * @return string Normalized DNS name. * @throws InvalidNameException If an invalid name or an IDN name without ext/intl being installed has been passed. */ function normalizeName(string $name): string { static $pattern = '/^(?[a-z0-9]([a-z0-9-_]{0,61}[a-z0-9])?)(\.(?&name))*\.?$/i'; if (\function_exists('idn_to_ascii') && \defined('INTL_IDNA_VARIANT_UTS46')) { if (false === $result = \idn_to_ascii($name, 0, \INTL_IDNA_VARIANT_UTS46)) { throw new InvalidNameException("Name '{$name}' could not be processed for IDN."); } $name = $result; } elseif (\preg_match('/[\x80-\xff]/', $name)) { throw new InvalidNameException( "Name '{$name}' contains non-ASCII characters and IDN support is not available. " . "Verify that ext/intl is installed for IDN support and that ICU is at least version 4.6." ); } if (isset($name[253]) || !\preg_match($pattern, $name)) { throw new InvalidNameException("Name '{$name}' is not a valid hostname."); } if ($name[-1] === '.') { $name = \substr($name, 0, -1); } return $name; }