Module ssh 

Support for tailnet-native, in-process SSH servers.

Overview

This module (tailscale::ssh) holds helpers for running SSH servers on the tailnet using russh. They delegate their functionality to the Handler trait, which is russh’s notion of a connection handler, i.e. a single incoming TCP connection gets a single instance of Handler.

Channels

SSH has a nested notion of channels, which are multiplexed over a single connection. The terminal session you open over a normal machine-to-machine ssh connection runs in a channel, and in principle, you can have multiple channels open on the same connection.

The channel_server module provides a ChannelServer type that separates out the per-channel handler logic from russh’s monolithic Handler. Channel handler logic is supported here by ChannelHandler, which is passed into ChannelServer and processes a ChannelEvent stream for each channel that’s opened.

Terminal applications

Support for building per-channel terminal application is provided by RatatuiTerm, which implements ChannelHandler to drive a ratatui::Terminal. The user provides an implementation of RatatuiApp that consumes input data and supports draws to the screen, and the RatatuiTerm drives it automatically.

Re-exports

pub extern crate russh;

Modules

recording

Session-recording transport for Tailscale SSH: stream a PTY session to a tsrecorder in asciinema CastV2 format.

Structs

ChannelContext

Everything a per-channel handler is told about the connection that opened it.

ChannelServer

Implementation of russh::server::Handler which provides per-channel session handlers using a parametric ChannelHandler.

RatatuiTerm

A ChannelHandler that runs a RatatuiApp.

ShellHandler

A turnkey ChannelHandler that runs the authorized user’s login shell in a PTY.

SshAccept

Details of an accepted SSH connection.

SshPolicy

An owned Tailscale SSH policy. Mirrors tailcfg.SSHPolicy.

SshRecorderFailureAction

What to do when session recording fails for an SshAction that has recorders configured. Mirrors tailcfg.SSHRecorderFailureAction.

Enums

ChannelEvent

An event that may be generated by a channel connected to a ChannelServer.

SshDecision

The outcome of evaluating an SshPolicy against a connection.

SshDenyReason

Why a connection was denied. Mirrors Go’s rejected / rejectedUser results plus an explicit reject action.

Traits

ChannelHandler

Handler for a channel session.

RatatuiApp

A ratatui application designed to be driven by a ChannelServer.

RatatuiEnv

Terminal environment for RatatuiApp.

TailnetServer

Trait to construct a new Handler from a Tailscale Device and the address of a connecting client.