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| 1 | +//! Run an SSH server hosting a custom TUI console that lets clients look up info about |
| 2 | +//! peers in the tailnet. |
| 3 | +
|
| 4 | +use std::{collections::VecDeque, net::IpAddr, path::PathBuf, sync::Arc}; |
| 5 | + |
| 6 | +use chrono::Datelike; |
| 7 | +use clap::Parser; |
| 8 | +use itertools::Itertools; |
| 9 | +use ratatui::{ |
| 10 | + Frame, |
| 11 | + layout::{Constraint, Layout}, |
| 12 | + macros::span, |
| 13 | + prelude::{Line, Span}, |
| 14 | + style::{Style, Stylize}, |
| 15 | + text::{Text, ToSpan}, |
| 16 | + widgets::{Block, List, ListItem, Paragraph}, |
| 17 | +}; |
| 18 | +use russh::keys::Algorithm; |
| 19 | +use tailscale::ssh; |
| 20 | +use tracing_subscriber::filter::LevelFilter; |
| 21 | +use ts_control::Node; |
| 22 | + |
| 23 | +/// Run an SSH server running a custom console over the tailnet supporting peer ip lookups. |
| 24 | +/// |
| 25 | +/// This does _no_ authentication -- anyone on the tailnet permitted to talk to the relevant |
| 26 | +/// port can connect. |
| 27 | +#[derive(clap::Parser)] |
| 28 | +#[command(version, about)] |
| 29 | +struct Args { |
| 30 | + /// Path to a key file to use. Will be created if it doesn't exist. |
| 31 | + #[arg(short = 'c', long, default_value = "tsrs_keys.json")] |
| 32 | + key_file: PathBuf, |
| 33 | + |
| 34 | + /// The auth key to connect with. |
| 35 | + /// |
| 36 | + /// Can be omitted if the key file is already authenticated. |
| 37 | + #[arg(short = 'k', long)] |
| 38 | + auth_key: Option<String>, |
| 39 | + |
| 40 | + /// Port to listen on (on tailnet IPv4). |
| 41 | + #[clap(short, long, default_value_t = 1234)] |
| 42 | + listen_port: u16, |
| 43 | +} |
| 44 | + |
| 45 | +#[derive(Default)] |
| 46 | +struct PeerLookupTui { |
| 47 | + input_state: String, |
| 48 | + messages: VecDeque<(String, Option<Node>)>, |
| 49 | +} |
| 50 | + |
| 51 | +impl ssh::RatatuiApp for PeerLookupTui { |
| 52 | + async fn input(&mut self, data: &[u8], env: impl ssh::RatatuiEnv) { |
| 53 | + let new_data = String::from_utf8_lossy(data); |
| 54 | + |
| 55 | + // NOTE(npry): this is essentially a manual terminal event parser. Ideally we'd hook this up |
| 56 | + // to one of the terminal crates' existing parsers, but none of them expose it. `crossterm` |
| 57 | + // (which we're using as our backend) has all the machinery to do it, but it's not exposed |
| 58 | + // as part of their API; instead, it's hardcoded to a system-specific implementation. |
| 59 | + // |
| 60 | + // Issue tracking this (https://github.com/crossterm-rs/crossterm/issues/694) has been open |
| 61 | + // since 2022. |
| 62 | + for c in new_data.chars() { |
| 63 | + match c { |
| 64 | + // ^C, ^D |
| 65 | + '\u{3}' | '\u{4}' => { |
| 66 | + tracing::debug!("got ^C or ^D, closing terminal"); |
| 67 | + env.close().await; |
| 68 | + return; |
| 69 | + } |
| 70 | + |
| 71 | + // BKSP |
| 72 | + '\u{8}' | '\u{7f}' => { |
| 73 | + if let Some((idx, _)) = self.input_state.char_indices().next_back() { |
| 74 | + self.input_state.truncate(idx); |
| 75 | + } |
| 76 | + } |
| 77 | + |
| 78 | + // ESC |
| 79 | + '\u{1b}' => { |
| 80 | + // punt, not implementing a full control sequence parser here |
| 81 | + } |
| 82 | + |
| 83 | + '\r' | '\n' => { |
| 84 | + let line = core::mem::take(&mut self.input_state); |
| 85 | + if line.is_empty() { |
| 86 | + continue; |
| 87 | + } |
| 88 | + |
| 89 | + tracing::trace!(query = line); |
| 90 | + |
| 91 | + let peer = env.tailscale().peer_by_name(&line).await.ok().flatten(); |
| 92 | + |
| 93 | + self.messages.truncate(31); |
| 94 | + self.messages.push_front((line, peer)); |
| 95 | + } |
| 96 | + c if !c.is_control() => { |
| 97 | + self.input_state.push(c); |
| 98 | + } |
| 99 | + _ignore => {} |
| 100 | + } |
| 101 | + } |
| 102 | + } |
| 103 | + |
| 104 | + fn draw(&mut self, frame: &mut Frame) { |
| 105 | + let layout = Layout::vertical([Constraint::Length(3), Constraint::Min(1)]); |
| 106 | + |
| 107 | + let [input_area, msg_area] = frame.area().layout(&layout); |
| 108 | + |
| 109 | + let input = Paragraph::new(Line::from_iter([ |
| 110 | + Span::raw(&self.input_state), |
| 111 | + '█'.slow_blink(), |
| 112 | + ])) |
| 113 | + .style(Style::default()) |
| 114 | + .block(Block::bordered().title("peer query")); |
| 115 | + |
| 116 | + frame.render_widget(input, input_area); |
| 117 | + |
| 118 | + #[allow(unstable_name_collisions)] |
| 119 | + let messages = self |
| 120 | + .messages |
| 121 | + .iter() |
| 122 | + .map(|(query, node)| ListItem::new(render_node(query, node.as_ref()))) |
| 123 | + .intersperse(ListItem::new("")) |
| 124 | + .collect::<Vec<_>>(); |
| 125 | + |
| 126 | + let messages = List::new(messages).block(Block::bordered().title("results")); |
| 127 | + |
| 128 | + frame.render_widget(messages, msg_area); |
| 129 | + } |
| 130 | +} |
| 131 | + |
| 132 | +fn render_node<'a>(query: &'a str, node: Option<&'a Node>) -> Text<'a> { |
| 133 | + let Some(node) = node else { |
| 134 | + return Text::from_iter([Line::from_iter([ |
| 135 | + span!(Style::new().red().bold(); "{query}"), |
| 136 | + span!(": no match"), |
| 137 | + ])]); |
| 138 | + }; |
| 139 | + |
| 140 | + let mut text = Text::from_iter([ |
| 141 | + Line::from_iter([ |
| 142 | + span!(Style::new().green().bold(); "{} ", node.fqdn(false)), |
| 143 | + span!("({})", node.stable_id.0), |
| 144 | + ":".into(), |
| 145 | + ]), |
| 146 | + Line::from_iter([ |
| 147 | + "ipv4: ".into(), |
| 148 | + node.tailnet_address.ipv4.to_span().light_cyan(), |
| 149 | + ]), |
| 150 | + Line::from_iter([ |
| 151 | + "ipv6: ".into(), |
| 152 | + node.tailnet_address.ipv6.to_span().light_cyan(), |
| 153 | + ]), |
| 154 | + Line::from_iter([ |
| 155 | + "node key: ".into(), |
| 156 | + node.node_key.to_span().yellow(), |
| 157 | + " (expires ".into(), |
| 158 | + if let Some(nk) = &node.node_key_expiry { |
| 159 | + span!("{}/{}/{}", nk.year(), nk.month(), nk.day()) |
| 160 | + } else { |
| 161 | + "never".red() |
| 162 | + }, |
| 163 | + ")".into(), |
| 164 | + ]), |
| 165 | + ]); |
| 166 | + |
| 167 | + if let Some(disco_key) = &node.disco_key { |
| 168 | + text.push_line(Line::from_iter([ |
| 169 | + "disco key: ".into(), |
| 170 | + disco_key.to_span().yellow(), |
| 171 | + ])); |
| 172 | + } |
| 173 | + |
| 174 | + if let Some(derp_region) = &node.derp_region { |
| 175 | + text.push_line(Line::from_iter([ |
| 176 | + "derp region: ".into(), |
| 177 | + derp_region.to_span().light_cyan(), |
| 178 | + ])); |
| 179 | + } |
| 180 | + |
| 181 | + if !node.tags.is_empty() { |
| 182 | + let mut line = Line::raw("tags: "); |
| 183 | + |
| 184 | + #[allow(unstable_name_collisions)] |
| 185 | + line.extend( |
| 186 | + node.tags |
| 187 | + .iter() |
| 188 | + .map(Span::raw) |
| 189 | + .map(|span| span.light_blue()) |
| 190 | + .intersperse(Span::raw(", ")), |
| 191 | + ); |
| 192 | + |
| 193 | + text.push_line(line); |
| 194 | + } |
| 195 | + |
| 196 | + text |
| 197 | +} |
| 198 | + |
| 199 | +#[tokio::main(flavor = "multi_thread")] |
| 200 | +async fn main() -> Result<(), Box<dyn core::error::Error>> { |
| 201 | + tracing_subscriber::fmt() |
| 202 | + .with_env_filter( |
| 203 | + tracing_subscriber::EnvFilter::builder() |
| 204 | + .with_default_directive(LevelFilter::INFO.into()) |
| 205 | + .from_env_lossy(), |
| 206 | + ) |
| 207 | + .init(); |
| 208 | + |
| 209 | + let args = Args::parse(); |
| 210 | + |
| 211 | + let dev = tailscale::Device::new( |
| 212 | + &tailscale::Config::default_with_key_file(&args.key_file).await?, |
| 213 | + args.auth_key, |
| 214 | + ) |
| 215 | + .await?; |
| 216 | + |
| 217 | + let ipv4: IpAddr = dev.ipv4_addr().await?.into(); |
| 218 | + let dev = Arc::new(dev); |
| 219 | + |
| 220 | + dev.serve_ssh_tui::<PeerLookupTui>( |
| 221 | + russh::server::Config { |
| 222 | + keys: vec![ |
| 223 | + russh::keys::PrivateKey::random(&mut rand::rng(), Algorithm::Ed25519).unwrap(), |
| 224 | + ], |
| 225 | + methods: russh::MethodSet::from(&[russh::MethodKind::None][..]), |
| 226 | + nodelay: true, |
| 227 | + ..Default::default() |
| 228 | + }, |
| 229 | + (ipv4, args.listen_port).into(), |
| 230 | + ) |
| 231 | + .await?; |
| 232 | + |
| 233 | + Ok(()) |
| 234 | +} |
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