class DlpIoError(Exception):
    """Base exception for dlp-io failures."""


class DlpConfigurationError(DlpIoError):
    """The bridge configuration is invalid for the current lifecycle state."""


class DlpHelperStartError(DlpIoError):
    """The approved Python helper could not be started."""


class DlpProtocolError(DlpIoError):
    """The helper and client exchanged an invalid protocol message."""


class DlpTransportError(DlpIoError):
    """The authenticated pipe stream failed before a valid EOF."""


class DlpSessionBusyError(DlpIoError):
    """A session already owns an active file stream."""