Struct HalfStream

pub(super) struct HalfStream {
    send_flow_control: StreamSendFlowControl,
    recvw: RecvWindow<StreamParams>,
    cmd_checker: Box<dyn CmdChecker + Send + 'static>,
}

Type to track state of half-closed streams.

A half-closed stream is one where we’ve sent an END cell, but where the other side might still send us data.

We need to track these streams instead of forgetting about them entirely, since otherwise we’d be vulnerable to a class of “DropMark” attacks; see https://gitlab.torproject.org/tpo/core/tor/-/issues/25573.

Fields

send_flow_control: StreamSendFlowControl

Send flow control for this stream. Used to detect whether we get too many SENDME cells.

recvw: RecvWindow<StreamParams>

Receive window for this stream. Used to detect whether we get too many data cells.

cmd_checker: Box<dyn CmdChecker + Send + 'static>

Object to tell us which cells to accept on this stream.

Implementations

impl HalfStream

pub(super) fn new( send_flow_control: StreamSendFlowControl, recvw: RecvWindow<StreamParams>, cmd_checker: Box<dyn CmdChecker + Send + 'static>, ) -> Self

Create a new half-closed stream.

pub(super) fn handle_msg( &mut self, msg: UnparsedRelayMsg, ) -> Result<StreamStatus>

Process an incoming message and adjust this HalfStream accordingly. Give an error if the protocol has been violated.

The caller must handle END cells; it is an internal error to pass END cells to this method. no ends here.

Trait Implementations

impl Debug for HalfStream

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.