Module sendme

Management for flow control windows.

Tor maintains a separate windows on circuits and on streams. These are controlled by SENDME cells, which (confusingly) are applied either at the circuit or the stream level depending on whether they have a stream ID set.

Circuit sendmes are authenticated: they include a cryptographic tag generated by the cryptography layer. This tag proves that the other side of the circuit really has read all of the data that it’s acknowledging.

Structs

CircParams 🔒

Parameters used for SENDME windows on circuits: limit at 1000 cells, and each SENDME adjusts by 100.

RecvWindow 🔒

Structure to track when we need to send SENDME cells for incoming data.

SendWindow 🔒

Tracks how many cells we can safely send on a circuit or stream.

SendmeValidator 🔒

Object used to validate SENDMEs as in managing the authenticated tag and verifying it.

StreamParams 🔒

Parameters used for SENDME windows on streams: limit at 500 cells, and each SENDME adjusts by 50.

Traits

WindowParams 🔒

Helper: parametrizes a window to determine its maximum and its increment.

Functions

cell_counts_towards_windows 🔒

Return true if this message is counted by flow-control windows.

cmd_counts_towards_windows 🔒

Return true if this message type is counted by flow-control windows.

Type Aliases

CircRecvWindow 🔒

A circuit’s receive window.

CircSendWindow 🔒

A circuit’s send window.

StreamRecvWindow 🔒

A stream’s receive window.

StreamSendWindow 🔒

A stream’s send window.