AFFiNE/packages/common/env/src/is-valid-ip-address.ts

export function isValidIPAddress(address: string) {
  if (address === 'localhost') {
    return true;
  }
  return /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(
    address
  );
}