ssh_session.rs

   1use crate::{
   2    json_log::LogRecord,
   3    protocol::{
   4        message_len_from_buffer, read_message_with_len, write_message, MessageId, MESSAGE_LEN_SIZE,
   5    },
   6    proxy::ProxyLaunchError,
   7};
   8use anyhow::{anyhow, Context as _, Result};
   9use async_trait::async_trait;
  10use collections::HashMap;
  11use futures::{
  12    channel::{
  13        mpsc::{self, Sender, UnboundedReceiver, UnboundedSender},
  14        oneshot,
  15    },
  16    future::{BoxFuture, Shared},
  17    select, select_biased, AsyncReadExt as _, Future, FutureExt as _, StreamExt as _,
  18};
  19use gpui::{
  20    App, AppContext, AsyncApp, BorrowAppContext, Context, Entity, EventEmitter, Global,
  21    SemanticVersion, Task, WeakEntity,
  22};
  23use itertools::Itertools;
  24use parking_lot::Mutex;
  25use paths;
  26use release_channel::{AppCommitSha, AppVersion, ReleaseChannel};
  27use rpc::{
  28    proto::{self, build_typed_envelope, Envelope, EnvelopedMessage, PeerId, RequestMessage},
  29    AnyProtoClient, EntityMessageSubscriber, ErrorExt, ProtoClient, ProtoMessageHandlerSet,
  30    RpcError,
  31};
  32use schemars::JsonSchema;
  33use serde::{Deserialize, Serialize};
  34use smol::{
  35    fs,
  36    process::{self, Child, Stdio},
  37};
  38use std::{
  39    any::TypeId,
  40    collections::VecDeque,
  41    fmt, iter,
  42    ops::ControlFlow,
  43    path::{Path, PathBuf},
  44    sync::{
  45        atomic::{AtomicU32, AtomicU64, Ordering::SeqCst},
  46        Arc, Weak,
  47    },
  48    time::{Duration, Instant},
  49};
  50use tempfile::TempDir;
  51use util::ResultExt;
  52
  53#[derive(
  54    Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy, serde::Serialize, serde::Deserialize,
  55)]
  56pub struct SshProjectId(pub u64);
  57
  58#[derive(Clone)]
  59pub struct SshSocket {
  60    connection_options: SshConnectionOptions,
  61    socket_path: PathBuf,
  62}
  63
  64#[derive(Debug, Clone, PartialEq, Eq, Hash, Deserialize, Serialize, JsonSchema)]
  65pub struct SshPortForwardOption {
  66    #[serde(skip_serializing_if = "Option::is_none")]
  67    pub local_host: Option<String>,
  68    pub local_port: u16,
  69    #[serde(skip_serializing_if = "Option::is_none")]
  70    pub remote_host: Option<String>,
  71    pub remote_port: u16,
  72}
  73
  74#[derive(Debug, Default, Clone, PartialEq, Eq, Hash)]
  75pub struct SshConnectionOptions {
  76    pub host: String,
  77    pub username: Option<String>,
  78    pub port: Option<u16>,
  79    pub password: Option<String>,
  80    pub args: Option<Vec<String>>,
  81    pub port_forwards: Option<Vec<SshPortForwardOption>>,
  82
  83    pub nickname: Option<String>,
  84    pub upload_binary_over_ssh: bool,
  85}
  86
  87#[macro_export]
  88macro_rules! shell_script {
  89    ($fmt:expr, $($name:ident = $arg:expr),+ $(,)?) => {{
  90        format!(
  91            $fmt,
  92            $(
  93                $name = shlex::try_quote($arg).unwrap()
  94            ),+
  95        )
  96    }};
  97}
  98
  99fn parse_port_number(port_str: &str) -> Result<u16> {
 100    port_str
 101        .parse()
 102        .map_err(|e| anyhow!("Invalid port number: {}: {}", port_str, e))
 103}
 104
 105fn parse_port_forward_spec(spec: &str) -> Result<SshPortForwardOption> {
 106    let parts: Vec<&str> = spec.split(':').collect();
 107
 108    match parts.len() {
 109        4 => {
 110            let local_port = parse_port_number(parts[1])?;
 111            let remote_port = parse_port_number(parts[3])?;
 112
 113            Ok(SshPortForwardOption {
 114                local_host: Some(parts[0].to_string()),
 115                local_port,
 116                remote_host: Some(parts[2].to_string()),
 117                remote_port,
 118            })
 119        }
 120        3 => {
 121            let local_port = parse_port_number(parts[0])?;
 122            let remote_port = parse_port_number(parts[2])?;
 123
 124            Ok(SshPortForwardOption {
 125                local_host: None,
 126                local_port,
 127                remote_host: Some(parts[1].to_string()),
 128                remote_port,
 129            })
 130        }
 131        _ => anyhow::bail!("Invalid port forward format"),
 132    }
 133}
 134
 135impl SshConnectionOptions {
 136    pub fn parse_command_line(input: &str) -> Result<Self> {
 137        let input = input.trim_start_matches("ssh ");
 138        let mut hostname: Option<String> = None;
 139        let mut username: Option<String> = None;
 140        let mut port: Option<u16> = None;
 141        let mut args = Vec::new();
 142        let mut port_forwards: Vec<SshPortForwardOption> = Vec::new();
 143
 144        // disallowed: -E, -e, -F, -f, -G, -g, -M, -N, -n, -O, -q, -S, -s, -T, -t, -V, -v, -W
 145        const ALLOWED_OPTS: &[&str] = &[
 146            "-4", "-6", "-A", "-a", "-C", "-K", "-k", "-X", "-x", "-Y", "-y",
 147        ];
 148        const ALLOWED_ARGS: &[&str] = &[
 149            "-B", "-b", "-c", "-D", "-I", "-i", "-J", "-l", "-m", "-o", "-P", "-p", "-R", "-w",
 150        ];
 151
 152        let mut tokens = shlex::split(input)
 153            .ok_or_else(|| anyhow!("invalid input"))?
 154            .into_iter();
 155
 156        'outer: while let Some(arg) = tokens.next() {
 157            if ALLOWED_OPTS.contains(&(&arg as &str)) {
 158                args.push(arg.to_string());
 159                continue;
 160            }
 161            if arg == "-p" {
 162                port = tokens.next().and_then(|arg| arg.parse().ok());
 163                continue;
 164            } else if let Some(p) = arg.strip_prefix("-p") {
 165                port = p.parse().ok();
 166                continue;
 167            }
 168            if arg == "-l" {
 169                username = tokens.next();
 170                continue;
 171            } else if let Some(l) = arg.strip_prefix("-l") {
 172                username = Some(l.to_string());
 173                continue;
 174            }
 175            if arg == "-L" || arg.starts_with("-L") {
 176                let forward_spec = if arg == "-L" {
 177                    tokens.next()
 178                } else {
 179                    Some(arg.strip_prefix("-L").unwrap().to_string())
 180                };
 181
 182                if let Some(spec) = forward_spec {
 183                    port_forwards.push(parse_port_forward_spec(&spec)?);
 184                } else {
 185                    anyhow::bail!("Missing port forward format");
 186                }
 187            }
 188
 189            for a in ALLOWED_ARGS {
 190                if arg == *a {
 191                    args.push(arg);
 192                    if let Some(next) = tokens.next() {
 193                        args.push(next);
 194                    }
 195                    continue 'outer;
 196                } else if arg.starts_with(a) {
 197                    args.push(arg);
 198                    continue 'outer;
 199                }
 200            }
 201            if arg.starts_with("-") || hostname.is_some() {
 202                anyhow::bail!("unsupported argument: {:?}", arg);
 203            }
 204            let mut input = &arg as &str;
 205            if let Some((u, rest)) = input.split_once('@') {
 206                input = rest;
 207                username = Some(u.to_string());
 208            }
 209            if let Some((rest, p)) = input.split_once(':') {
 210                input = rest;
 211                port = p.parse().ok()
 212            }
 213            hostname = Some(input.to_string())
 214        }
 215
 216        let Some(hostname) = hostname else {
 217            anyhow::bail!("missing hostname");
 218        };
 219
 220        let port_forwards = match port_forwards.len() {
 221            0 => None,
 222            _ => Some(port_forwards),
 223        };
 224
 225        Ok(Self {
 226            host: hostname.to_string(),
 227            username: username.clone(),
 228            port,
 229            port_forwards,
 230            args: Some(args),
 231            password: None,
 232            nickname: None,
 233            upload_binary_over_ssh: false,
 234        })
 235    }
 236
 237    pub fn ssh_url(&self) -> String {
 238        let mut result = String::from("ssh://");
 239        if let Some(username) = &self.username {
 240            result.push_str(username);
 241            result.push('@');
 242        }
 243        result.push_str(&self.host);
 244        if let Some(port) = self.port {
 245            result.push(':');
 246            result.push_str(&port.to_string());
 247        }
 248        result
 249    }
 250
 251    pub fn additional_args(&self) -> Vec<String> {
 252        let mut args = self.args.iter().flatten().cloned().collect::<Vec<String>>();
 253
 254        if let Some(forwards) = &self.port_forwards {
 255            args.extend(forwards.iter().map(|pf| {
 256                let local_host = match &pf.local_host {
 257                    Some(host) => host,
 258                    None => "localhost",
 259                };
 260                let remote_host = match &pf.remote_host {
 261                    Some(host) => host,
 262                    None => "localhost",
 263                };
 264
 265                format!(
 266                    "-L{}:{}:{}:{}",
 267                    local_host, pf.local_port, remote_host, pf.remote_port
 268                )
 269            }));
 270        }
 271
 272        args
 273    }
 274
 275    fn scp_url(&self) -> String {
 276        if let Some(username) = &self.username {
 277            format!("{}@{}", username, self.host)
 278        } else {
 279            self.host.clone()
 280        }
 281    }
 282
 283    pub fn connection_string(&self) -> String {
 284        let host = if let Some(username) = &self.username {
 285            format!("{}@{}", username, self.host)
 286        } else {
 287            self.host.clone()
 288        };
 289        if let Some(port) = &self.port {
 290            format!("{}:{}", host, port)
 291        } else {
 292            host
 293        }
 294    }
 295}
 296
 297#[derive(Copy, Clone, Debug)]
 298pub struct SshPlatform {
 299    pub os: &'static str,
 300    pub arch: &'static str,
 301}
 302
 303impl SshPlatform {
 304    pub fn triple(&self) -> Option<String> {
 305        Some(format!(
 306            "{}-{}",
 307            self.arch,
 308            match self.os {
 309                "linux" => "unknown-linux-gnu",
 310                "macos" => "apple-darwin",
 311                _ => return None,
 312            }
 313        ))
 314    }
 315}
 316
 317pub trait SshClientDelegate: Send + Sync {
 318    fn ask_password(&self, prompt: String, cx: &mut AsyncApp) -> oneshot::Receiver<Result<String>>;
 319    fn get_download_params(
 320        &self,
 321        platform: SshPlatform,
 322        release_channel: ReleaseChannel,
 323        version: Option<SemanticVersion>,
 324        cx: &mut AsyncApp,
 325    ) -> Task<Result<Option<(String, String)>>>;
 326
 327    fn download_server_binary_locally(
 328        &self,
 329        platform: SshPlatform,
 330        release_channel: ReleaseChannel,
 331        version: Option<SemanticVersion>,
 332        cx: &mut AsyncApp,
 333    ) -> Task<Result<PathBuf>>;
 334    fn set_status(&self, status: Option<&str>, cx: &mut AsyncApp);
 335}
 336
 337impl SshSocket {
 338    // :WARNING: ssh unquotes arguments when executing on the remote :WARNING:
 339    // e.g. $ ssh host sh -c 'ls -l' is equivalent to $ ssh host sh -c ls -l
 340    // and passes -l as an argument to sh, not to ls.
 341    // Furthermore, some setups (e.g. Coder) will change directory when SSH'ing
 342    // into a machine. You must use `cd` to get back to $HOME.
 343    // You need to do it like this: $ ssh host "cd; sh -c 'ls -l /tmp'"
 344    fn ssh_command(&self, program: &str, args: &[&str]) -> process::Command {
 345        let mut command = util::command::new_smol_command("ssh");
 346        let to_run = iter::once(&program)
 347            .chain(args.iter())
 348            .map(|token| {
 349                // We're trying to work with: sh, bash, zsh, fish, tcsh, ...?
 350                debug_assert!(
 351                    !token.contains('\n'),
 352                    "multiline arguments do not work in all shells"
 353                );
 354                shlex::try_quote(token).unwrap()
 355            })
 356            .join(" ");
 357        let to_run = format!("cd; {to_run}");
 358        log::debug!("ssh {} {:?}", self.connection_options.ssh_url(), to_run);
 359        self.ssh_options(&mut command)
 360            .arg(self.connection_options.ssh_url())
 361            .arg(to_run);
 362        command
 363    }
 364
 365    async fn run_command(&self, program: &str, args: &[&str]) -> Result<String> {
 366        let output = self.ssh_command(program, args).output().await?;
 367        if output.status.success() {
 368            Ok(String::from_utf8_lossy(&output.stdout).to_string())
 369        } else {
 370            Err(anyhow!(
 371                "failed to run command: {}",
 372                String::from_utf8_lossy(&output.stderr)
 373            ))
 374        }
 375    }
 376
 377    fn ssh_options<'a>(&self, command: &'a mut process::Command) -> &'a mut process::Command {
 378        command
 379            .stdin(Stdio::piped())
 380            .stdout(Stdio::piped())
 381            .stderr(Stdio::piped())
 382            .args(["-o", "ControlMaster=no", "-o"])
 383            .arg(format!("ControlPath={}", self.socket_path.display()))
 384    }
 385
 386    fn ssh_args(&self) -> Vec<String> {
 387        vec![
 388            "-o".to_string(),
 389            "ControlMaster=no".to_string(),
 390            "-o".to_string(),
 391            format!("ControlPath={}", self.socket_path.display()),
 392            self.connection_options.ssh_url(),
 393        ]
 394    }
 395}
 396
 397const MAX_MISSED_HEARTBEATS: usize = 5;
 398const HEARTBEAT_INTERVAL: Duration = Duration::from_secs(5);
 399const HEARTBEAT_TIMEOUT: Duration = Duration::from_secs(5);
 400
 401const MAX_RECONNECT_ATTEMPTS: usize = 3;
 402
 403enum State {
 404    Connecting,
 405    Connected {
 406        ssh_connection: Arc<dyn RemoteConnection>,
 407        delegate: Arc<dyn SshClientDelegate>,
 408
 409        multiplex_task: Task<Result<()>>,
 410        heartbeat_task: Task<Result<()>>,
 411    },
 412    HeartbeatMissed {
 413        missed_heartbeats: usize,
 414
 415        ssh_connection: Arc<dyn RemoteConnection>,
 416        delegate: Arc<dyn SshClientDelegate>,
 417
 418        multiplex_task: Task<Result<()>>,
 419        heartbeat_task: Task<Result<()>>,
 420    },
 421    Reconnecting,
 422    ReconnectFailed {
 423        ssh_connection: Arc<dyn RemoteConnection>,
 424        delegate: Arc<dyn SshClientDelegate>,
 425
 426        error: anyhow::Error,
 427        attempts: usize,
 428    },
 429    ReconnectExhausted,
 430    ServerNotRunning,
 431}
 432
 433impl fmt::Display for State {
 434    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 435        match self {
 436            Self::Connecting => write!(f, "connecting"),
 437            Self::Connected { .. } => write!(f, "connected"),
 438            Self::Reconnecting => write!(f, "reconnecting"),
 439            Self::ReconnectFailed { .. } => write!(f, "reconnect failed"),
 440            Self::ReconnectExhausted => write!(f, "reconnect exhausted"),
 441            Self::HeartbeatMissed { .. } => write!(f, "heartbeat missed"),
 442            Self::ServerNotRunning { .. } => write!(f, "server not running"),
 443        }
 444    }
 445}
 446
 447impl State {
 448    fn ssh_connection(&self) -> Option<&dyn RemoteConnection> {
 449        match self {
 450            Self::Connected { ssh_connection, .. } => Some(ssh_connection.as_ref()),
 451            Self::HeartbeatMissed { ssh_connection, .. } => Some(ssh_connection.as_ref()),
 452            Self::ReconnectFailed { ssh_connection, .. } => Some(ssh_connection.as_ref()),
 453            _ => None,
 454        }
 455    }
 456
 457    fn can_reconnect(&self) -> bool {
 458        match self {
 459            Self::Connected { .. }
 460            | Self::HeartbeatMissed { .. }
 461            | Self::ReconnectFailed { .. } => true,
 462            State::Connecting
 463            | State::Reconnecting
 464            | State::ReconnectExhausted
 465            | State::ServerNotRunning => false,
 466        }
 467    }
 468
 469    fn is_reconnect_failed(&self) -> bool {
 470        matches!(self, Self::ReconnectFailed { .. })
 471    }
 472
 473    fn is_reconnect_exhausted(&self) -> bool {
 474        matches!(self, Self::ReconnectExhausted { .. })
 475    }
 476
 477    fn is_server_not_running(&self) -> bool {
 478        matches!(self, Self::ServerNotRunning)
 479    }
 480
 481    fn is_reconnecting(&self) -> bool {
 482        matches!(self, Self::Reconnecting { .. })
 483    }
 484
 485    fn heartbeat_recovered(self) -> Self {
 486        match self {
 487            Self::HeartbeatMissed {
 488                ssh_connection,
 489                delegate,
 490                multiplex_task,
 491                heartbeat_task,
 492                ..
 493            } => Self::Connected {
 494                ssh_connection,
 495                delegate,
 496                multiplex_task,
 497                heartbeat_task,
 498            },
 499            _ => self,
 500        }
 501    }
 502
 503    fn heartbeat_missed(self) -> Self {
 504        match self {
 505            Self::Connected {
 506                ssh_connection,
 507                delegate,
 508                multiplex_task,
 509                heartbeat_task,
 510            } => Self::HeartbeatMissed {
 511                missed_heartbeats: 1,
 512                ssh_connection,
 513                delegate,
 514                multiplex_task,
 515                heartbeat_task,
 516            },
 517            Self::HeartbeatMissed {
 518                missed_heartbeats,
 519                ssh_connection,
 520                delegate,
 521                multiplex_task,
 522                heartbeat_task,
 523            } => Self::HeartbeatMissed {
 524                missed_heartbeats: missed_heartbeats + 1,
 525                ssh_connection,
 526                delegate,
 527                multiplex_task,
 528                heartbeat_task,
 529            },
 530            _ => self,
 531        }
 532    }
 533}
 534
 535/// The state of the ssh connection.
 536#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 537pub enum ConnectionState {
 538    Connecting,
 539    Connected,
 540    HeartbeatMissed,
 541    Reconnecting,
 542    Disconnected,
 543}
 544
 545impl From<&State> for ConnectionState {
 546    fn from(value: &State) -> Self {
 547        match value {
 548            State::Connecting => Self::Connecting,
 549            State::Connected { .. } => Self::Connected,
 550            State::Reconnecting | State::ReconnectFailed { .. } => Self::Reconnecting,
 551            State::HeartbeatMissed { .. } => Self::HeartbeatMissed,
 552            State::ReconnectExhausted => Self::Disconnected,
 553            State::ServerNotRunning => Self::Disconnected,
 554        }
 555    }
 556}
 557
 558pub struct SshRemoteClient {
 559    client: Arc<ChannelClient>,
 560    unique_identifier: String,
 561    connection_options: SshConnectionOptions,
 562    state: Arc<Mutex<Option<State>>>,
 563}
 564
 565#[derive(Debug)]
 566pub enum SshRemoteEvent {
 567    Disconnected,
 568}
 569
 570impl EventEmitter<SshRemoteEvent> for SshRemoteClient {}
 571
 572// Identifies the socket on the remote server so that reconnects
 573// can re-join the same project.
 574pub enum ConnectionIdentifier {
 575    Setup(u64),
 576    Workspace(i64),
 577}
 578
 579static NEXT_ID: AtomicU64 = AtomicU64::new(1);
 580
 581impl ConnectionIdentifier {
 582    pub fn setup() -> Self {
 583        Self::Setup(NEXT_ID.fetch_add(1, SeqCst))
 584    }
 585    // This string gets used in a socket name, and so must be relatively short.
 586    // The total length of:
 587    //   /home/{username}/.local/share/zed/server_state/{name}/stdout.sock
 588    // Must be less than about 100 characters
 589    //   https://unix.stackexchange.com/questions/367008/why-is-socket-path-length-limited-to-a-hundred-chars
 590    // So our strings should be at most 20 characters or so.
 591    fn to_string(&self, cx: &App) -> String {
 592        let identifier_prefix = match ReleaseChannel::global(cx) {
 593            ReleaseChannel::Stable => "".to_string(),
 594            release_channel => format!("{}-", release_channel.dev_name()),
 595        };
 596        match self {
 597            Self::Setup(setup_id) => format!("{identifier_prefix}setup-{setup_id}"),
 598            Self::Workspace(workspace_id) => {
 599                format!("{identifier_prefix}workspace-{workspace_id}",)
 600            }
 601        }
 602    }
 603}
 604
 605impl SshRemoteClient {
 606    pub fn new(
 607        unique_identifier: ConnectionIdentifier,
 608        connection_options: SshConnectionOptions,
 609        cancellation: oneshot::Receiver<()>,
 610        delegate: Arc<dyn SshClientDelegate>,
 611        cx: &mut App,
 612    ) -> Task<Result<Option<Entity<Self>>>> {
 613        let unique_identifier = unique_identifier.to_string(cx);
 614        cx.spawn(|mut cx| async move {
 615            let success = Box::pin(async move {
 616                let (outgoing_tx, outgoing_rx) = mpsc::unbounded::<Envelope>();
 617                let (incoming_tx, incoming_rx) = mpsc::unbounded::<Envelope>();
 618                let (connection_activity_tx, connection_activity_rx) = mpsc::channel::<()>(1);
 619
 620                let client =
 621                    cx.update(|cx| ChannelClient::new(incoming_rx, outgoing_tx, cx, "client"))?;
 622                let this = cx.new(|_| Self {
 623                    client: client.clone(),
 624                    unique_identifier: unique_identifier.clone(),
 625                    connection_options: connection_options.clone(),
 626                    state: Arc::new(Mutex::new(Some(State::Connecting))),
 627                })?;
 628
 629                let ssh_connection = cx
 630                    .update(|cx| {
 631                        cx.update_default_global(|pool: &mut ConnectionPool, cx| {
 632                            pool.connect(connection_options, &delegate, cx)
 633                        })
 634                    })?
 635                    .await
 636                    .map_err(|e| e.cloned())?;
 637
 638                let io_task = ssh_connection.start_proxy(
 639                    unique_identifier,
 640                    false,
 641                    incoming_tx,
 642                    outgoing_rx,
 643                    connection_activity_tx,
 644                    delegate.clone(),
 645                    &mut cx,
 646                );
 647
 648                let multiplex_task = Self::monitor(this.downgrade(), io_task, &cx);
 649
 650                if let Err(error) = client.ping(HEARTBEAT_TIMEOUT).await {
 651                    log::error!("failed to establish connection: {}", error);
 652                    return Err(error);
 653                }
 654
 655                let heartbeat_task =
 656                    Self::heartbeat(this.downgrade(), connection_activity_rx, &mut cx);
 657
 658                this.update(&mut cx, |this, _| {
 659                    *this.state.lock() = Some(State::Connected {
 660                        ssh_connection,
 661                        delegate,
 662                        multiplex_task,
 663                        heartbeat_task,
 664                    });
 665                })?;
 666
 667                Ok(Some(this))
 668            });
 669
 670            select! {
 671                _ = cancellation.fuse() => {
 672                    Ok(None)
 673                }
 674                result = success.fuse() =>  result
 675            }
 676        })
 677    }
 678
 679    pub fn shutdown_processes<T: RequestMessage>(
 680        &self,
 681        shutdown_request: Option<T>,
 682    ) -> Option<impl Future<Output = ()>> {
 683        let state = self.state.lock().take()?;
 684        log::info!("shutting down ssh processes");
 685
 686        let State::Connected {
 687            multiplex_task,
 688            heartbeat_task,
 689            ssh_connection,
 690            delegate,
 691        } = state
 692        else {
 693            return None;
 694        };
 695
 696        let client = self.client.clone();
 697
 698        Some(async move {
 699            if let Some(shutdown_request) = shutdown_request {
 700                client.send(shutdown_request).log_err();
 701                // We wait 50ms instead of waiting for a response, because
 702                // waiting for a response would require us to wait on the main thread
 703                // which we want to avoid in an `on_app_quit` callback.
 704                smol::Timer::after(Duration::from_millis(50)).await;
 705            }
 706
 707            // Drop `multiplex_task` because it owns our ssh_proxy_process, which is a
 708            // child of master_process.
 709            drop(multiplex_task);
 710            // Now drop the rest of state, which kills master process.
 711            drop(heartbeat_task);
 712            drop(ssh_connection);
 713            drop(delegate);
 714        })
 715    }
 716
 717    fn reconnect(&mut self, cx: &mut Context<Self>) -> Result<()> {
 718        let mut lock = self.state.lock();
 719
 720        let can_reconnect = lock
 721            .as_ref()
 722            .map(|state| state.can_reconnect())
 723            .unwrap_or(false);
 724        if !can_reconnect {
 725            let error = if let Some(state) = lock.as_ref() {
 726                format!("invalid state, cannot reconnect while in state {state}")
 727            } else {
 728                "no state set".to_string()
 729            };
 730            log::info!("aborting reconnect, because not in state that allows reconnecting");
 731            return Err(anyhow!(error));
 732        }
 733
 734        let state = lock.take().unwrap();
 735        let (attempts, ssh_connection, delegate) = match state {
 736            State::Connected {
 737                ssh_connection,
 738                delegate,
 739                multiplex_task,
 740                heartbeat_task,
 741            }
 742            | State::HeartbeatMissed {
 743                ssh_connection,
 744                delegate,
 745                multiplex_task,
 746                heartbeat_task,
 747                ..
 748            } => {
 749                drop(multiplex_task);
 750                drop(heartbeat_task);
 751                (0, ssh_connection, delegate)
 752            }
 753            State::ReconnectFailed {
 754                attempts,
 755                ssh_connection,
 756                delegate,
 757                ..
 758            } => (attempts, ssh_connection, delegate),
 759            State::Connecting
 760            | State::Reconnecting
 761            | State::ReconnectExhausted
 762            | State::ServerNotRunning => unreachable!(),
 763        };
 764
 765        let attempts = attempts + 1;
 766        if attempts > MAX_RECONNECT_ATTEMPTS {
 767            log::error!(
 768                "Failed to reconnect to after {} attempts, giving up",
 769                MAX_RECONNECT_ATTEMPTS
 770            );
 771            drop(lock);
 772            self.set_state(State::ReconnectExhausted, cx);
 773            return Ok(());
 774        }
 775        drop(lock);
 776
 777        self.set_state(State::Reconnecting, cx);
 778
 779        log::info!("Trying to reconnect to ssh server... Attempt {}", attempts);
 780
 781        let unique_identifier = self.unique_identifier.clone();
 782        let client = self.client.clone();
 783        let reconnect_task = cx.spawn(|this, mut cx| async move {
 784            macro_rules! failed {
 785                ($error:expr, $attempts:expr, $ssh_connection:expr, $delegate:expr) => {
 786                    return State::ReconnectFailed {
 787                        error: anyhow!($error),
 788                        attempts: $attempts,
 789                        ssh_connection: $ssh_connection,
 790                        delegate: $delegate,
 791                    };
 792                };
 793            }
 794
 795            if let Err(error) = ssh_connection
 796                .kill()
 797                .await
 798                .context("Failed to kill ssh process")
 799            {
 800                failed!(error, attempts, ssh_connection, delegate);
 801            };
 802
 803            let connection_options = ssh_connection.connection_options();
 804
 805            let (outgoing_tx, outgoing_rx) = mpsc::unbounded::<Envelope>();
 806            let (incoming_tx, incoming_rx) = mpsc::unbounded::<Envelope>();
 807            let (connection_activity_tx, connection_activity_rx) = mpsc::channel::<()>(1);
 808
 809            let (ssh_connection, io_task) = match async {
 810                let ssh_connection = cx
 811                    .update_global(|pool: &mut ConnectionPool, cx| {
 812                        pool.connect(connection_options, &delegate, cx)
 813                    })?
 814                    .await
 815                    .map_err(|error| error.cloned())?;
 816
 817                let io_task = ssh_connection.start_proxy(
 818                    unique_identifier,
 819                    true,
 820                    incoming_tx,
 821                    outgoing_rx,
 822                    connection_activity_tx,
 823                    delegate.clone(),
 824                    &mut cx,
 825                );
 826                anyhow::Ok((ssh_connection, io_task))
 827            }
 828            .await
 829            {
 830                Ok((ssh_connection, io_task)) => (ssh_connection, io_task),
 831                Err(error) => {
 832                    failed!(error, attempts, ssh_connection, delegate);
 833                }
 834            };
 835
 836            let multiplex_task = Self::monitor(this.clone(), io_task, &cx);
 837            client.reconnect(incoming_rx, outgoing_tx, &cx);
 838
 839            if let Err(error) = client.resync(HEARTBEAT_TIMEOUT).await {
 840                failed!(error, attempts, ssh_connection, delegate);
 841            };
 842
 843            State::Connected {
 844                ssh_connection,
 845                delegate,
 846                multiplex_task,
 847                heartbeat_task: Self::heartbeat(this.clone(), connection_activity_rx, &mut cx),
 848            }
 849        });
 850
 851        cx.spawn(|this, mut cx| async move {
 852            let new_state = reconnect_task.await;
 853            this.update(&mut cx, |this, cx| {
 854                this.try_set_state(cx, |old_state| {
 855                    if old_state.is_reconnecting() {
 856                        match &new_state {
 857                            State::Connecting
 858                            | State::Reconnecting { .. }
 859                            | State::HeartbeatMissed { .. }
 860                            | State::ServerNotRunning => {}
 861                            State::Connected { .. } => {
 862                                log::info!("Successfully reconnected");
 863                            }
 864                            State::ReconnectFailed {
 865                                error, attempts, ..
 866                            } => {
 867                                log::error!(
 868                                    "Reconnect attempt {} failed: {:?}. Starting new attempt...",
 869                                    attempts,
 870                                    error
 871                                );
 872                            }
 873                            State::ReconnectExhausted => {
 874                                log::error!("Reconnect attempt failed and all attempts exhausted");
 875                            }
 876                        }
 877                        Some(new_state)
 878                    } else {
 879                        None
 880                    }
 881                });
 882
 883                if this.state_is(State::is_reconnect_failed) {
 884                    this.reconnect(cx)
 885                } else if this.state_is(State::is_reconnect_exhausted) {
 886                    Ok(())
 887                } else {
 888                    log::debug!("State has transition from Reconnecting into new state while attempting reconnect.");
 889                    Ok(())
 890                }
 891            })
 892        })
 893        .detach_and_log_err(cx);
 894
 895        Ok(())
 896    }
 897
 898    fn heartbeat(
 899        this: WeakEntity<Self>,
 900        mut connection_activity_rx: mpsc::Receiver<()>,
 901        cx: &mut AsyncApp,
 902    ) -> Task<Result<()>> {
 903        let Ok(client) = this.update(cx, |this, _| this.client.clone()) else {
 904            return Task::ready(Err(anyhow!("SshRemoteClient lost")));
 905        };
 906
 907        cx.spawn(|mut cx| {
 908            let this = this.clone();
 909            async move {
 910                let mut missed_heartbeats = 0;
 911
 912                let keepalive_timer = cx.background_executor().timer(HEARTBEAT_INTERVAL).fuse();
 913                futures::pin_mut!(keepalive_timer);
 914
 915                loop {
 916                    select_biased! {
 917                        result = connection_activity_rx.next().fuse() => {
 918                            if result.is_none() {
 919                                log::warn!("ssh heartbeat: connection activity channel has been dropped. stopping.");
 920                                return Ok(());
 921                            }
 922
 923                            if missed_heartbeats != 0 {
 924                                missed_heartbeats = 0;
 925                                this.update(&mut cx, |this, mut cx| {
 926                                    this.handle_heartbeat_result(missed_heartbeats, &mut cx)
 927                                })?;
 928                            }
 929                        }
 930                        _ = keepalive_timer => {
 931                            log::debug!("Sending heartbeat to server...");
 932
 933                            let result = select_biased! {
 934                                _ = connection_activity_rx.next().fuse() => {
 935                                    Ok(())
 936                                }
 937                                ping_result = client.ping(HEARTBEAT_TIMEOUT).fuse() => {
 938                                    ping_result
 939                                }
 940                            };
 941
 942                            if result.is_err() {
 943                                missed_heartbeats += 1;
 944                                log::warn!(
 945                                    "No heartbeat from server after {:?}. Missed heartbeat {} out of {}.",
 946                                    HEARTBEAT_TIMEOUT,
 947                                    missed_heartbeats,
 948                                    MAX_MISSED_HEARTBEATS
 949                                );
 950                            } else if missed_heartbeats != 0 {
 951                                missed_heartbeats = 0;
 952                            } else {
 953                                continue;
 954                            }
 955
 956                            let result = this.update(&mut cx, |this, mut cx| {
 957                                this.handle_heartbeat_result(missed_heartbeats, &mut cx)
 958                            })?;
 959                            if result.is_break() {
 960                                return Ok(());
 961                            }
 962                        }
 963                    }
 964
 965                    keepalive_timer.set(cx.background_executor().timer(HEARTBEAT_INTERVAL).fuse());
 966                }
 967            }
 968        })
 969    }
 970
 971    fn handle_heartbeat_result(
 972        &mut self,
 973        missed_heartbeats: usize,
 974        cx: &mut Context<Self>,
 975    ) -> ControlFlow<()> {
 976        let state = self.state.lock().take().unwrap();
 977        let next_state = if missed_heartbeats > 0 {
 978            state.heartbeat_missed()
 979        } else {
 980            state.heartbeat_recovered()
 981        };
 982
 983        self.set_state(next_state, cx);
 984
 985        if missed_heartbeats >= MAX_MISSED_HEARTBEATS {
 986            log::error!(
 987                "Missed last {} heartbeats. Reconnecting...",
 988                missed_heartbeats
 989            );
 990
 991            self.reconnect(cx)
 992                .context("failed to start reconnect process after missing heartbeats")
 993                .log_err();
 994            ControlFlow::Break(())
 995        } else {
 996            ControlFlow::Continue(())
 997        }
 998    }
 999
1000    fn monitor(
1001        this: WeakEntity<Self>,
1002        io_task: Task<Result<i32>>,
1003        cx: &AsyncApp,
1004    ) -> Task<Result<()>> {
1005        cx.spawn(|mut cx| async move {
1006            let result = io_task.await;
1007
1008            match result {
1009                Ok(exit_code) => {
1010                    if let Some(error) = ProxyLaunchError::from_exit_code(exit_code) {
1011                        match error {
1012                            ProxyLaunchError::ServerNotRunning => {
1013                                log::error!("failed to reconnect because server is not running");
1014                                this.update(&mut cx, |this, cx| {
1015                                    this.set_state(State::ServerNotRunning, cx);
1016                                })?;
1017                            }
1018                        }
1019                    } else if exit_code > 0 {
1020                        log::error!("proxy process terminated unexpectedly");
1021                        this.update(&mut cx, |this, cx| {
1022                            this.reconnect(cx).ok();
1023                        })?;
1024                    }
1025                }
1026                Err(error) => {
1027                    log::warn!("ssh io task died with error: {:?}. reconnecting...", error);
1028                    this.update(&mut cx, |this, cx| {
1029                        this.reconnect(cx).ok();
1030                    })?;
1031                }
1032            }
1033
1034            Ok(())
1035        })
1036    }
1037
1038    fn state_is(&self, check: impl FnOnce(&State) -> bool) -> bool {
1039        self.state.lock().as_ref().map_or(false, check)
1040    }
1041
1042    fn try_set_state(&self, cx: &mut Context<Self>, map: impl FnOnce(&State) -> Option<State>) {
1043        let mut lock = self.state.lock();
1044        let new_state = lock.as_ref().and_then(map);
1045
1046        if let Some(new_state) = new_state {
1047            lock.replace(new_state);
1048            cx.notify();
1049        }
1050    }
1051
1052    fn set_state(&self, state: State, cx: &mut Context<Self>) {
1053        log::info!("setting state to '{}'", &state);
1054
1055        let is_reconnect_exhausted = state.is_reconnect_exhausted();
1056        let is_server_not_running = state.is_server_not_running();
1057        self.state.lock().replace(state);
1058
1059        if is_reconnect_exhausted || is_server_not_running {
1060            cx.emit(SshRemoteEvent::Disconnected);
1061        }
1062        cx.notify();
1063    }
1064
1065    pub fn subscribe_to_entity<E: 'static>(&self, remote_id: u64, entity: &Entity<E>) {
1066        self.client.subscribe_to_entity(remote_id, entity);
1067    }
1068
1069    pub fn ssh_args(&self) -> Option<Vec<String>> {
1070        self.state
1071            .lock()
1072            .as_ref()
1073            .and_then(|state| state.ssh_connection())
1074            .map(|ssh_connection| ssh_connection.ssh_args())
1075    }
1076
1077    pub fn upload_directory(
1078        &self,
1079        src_path: PathBuf,
1080        dest_path: PathBuf,
1081        cx: &App,
1082    ) -> Task<Result<()>> {
1083        let state = self.state.lock();
1084        let Some(connection) = state.as_ref().and_then(|state| state.ssh_connection()) else {
1085            return Task::ready(Err(anyhow!("no ssh connection")));
1086        };
1087        connection.upload_directory(src_path, dest_path, cx)
1088    }
1089
1090    pub fn proto_client(&self) -> AnyProtoClient {
1091        self.client.clone().into()
1092    }
1093
1094    pub fn connection_string(&self) -> String {
1095        self.connection_options.connection_string()
1096    }
1097
1098    pub fn connection_options(&self) -> SshConnectionOptions {
1099        self.connection_options.clone()
1100    }
1101
1102    pub fn connection_state(&self) -> ConnectionState {
1103        self.state
1104            .lock()
1105            .as_ref()
1106            .map(ConnectionState::from)
1107            .unwrap_or(ConnectionState::Disconnected)
1108    }
1109
1110    pub fn is_disconnected(&self) -> bool {
1111        self.connection_state() == ConnectionState::Disconnected
1112    }
1113
1114    #[cfg(any(test, feature = "test-support"))]
1115    pub fn simulate_disconnect(&self, client_cx: &mut App) -> Task<()> {
1116        let opts = self.connection_options();
1117        client_cx.spawn(|cx| async move {
1118            let connection = cx
1119                .update_global(|c: &mut ConnectionPool, _| {
1120                    if let Some(ConnectionPoolEntry::Connecting(c)) = c.connections.get(&opts) {
1121                        c.clone()
1122                    } else {
1123                        panic!("missing test connection")
1124                    }
1125                })
1126                .unwrap()
1127                .await
1128                .unwrap();
1129
1130            connection.simulate_disconnect(&cx);
1131        })
1132    }
1133
1134    #[cfg(any(test, feature = "test-support"))]
1135    pub fn fake_server(
1136        client_cx: &mut gpui::TestAppContext,
1137        server_cx: &mut gpui::TestAppContext,
1138    ) -> (SshConnectionOptions, Arc<ChannelClient>) {
1139        let port = client_cx
1140            .update(|cx| cx.default_global::<ConnectionPool>().connections.len() as u16 + 1);
1141        let opts = SshConnectionOptions {
1142            host: "<fake>".to_string(),
1143            port: Some(port),
1144            ..Default::default()
1145        };
1146        let (outgoing_tx, _) = mpsc::unbounded::<Envelope>();
1147        let (_, incoming_rx) = mpsc::unbounded::<Envelope>();
1148        let server_client =
1149            server_cx.update(|cx| ChannelClient::new(incoming_rx, outgoing_tx, cx, "fake-server"));
1150        let connection: Arc<dyn RemoteConnection> = Arc::new(fake::FakeRemoteConnection {
1151            connection_options: opts.clone(),
1152            server_cx: fake::SendableCx::new(server_cx),
1153            server_channel: server_client.clone(),
1154        });
1155
1156        client_cx.update(|cx| {
1157            cx.update_default_global(|c: &mut ConnectionPool, cx| {
1158                c.connections.insert(
1159                    opts.clone(),
1160                    ConnectionPoolEntry::Connecting(
1161                        cx.background_executor()
1162                            .spawn({
1163                                let connection = connection.clone();
1164                                async move { Ok(connection.clone()) }
1165                            })
1166                            .shared(),
1167                    ),
1168                );
1169            })
1170        });
1171
1172        (opts, server_client)
1173    }
1174
1175    #[cfg(any(test, feature = "test-support"))]
1176    pub async fn fake_client(
1177        opts: SshConnectionOptions,
1178        client_cx: &mut gpui::TestAppContext,
1179    ) -> Entity<Self> {
1180        let (_tx, rx) = oneshot::channel();
1181        client_cx
1182            .update(|cx| {
1183                Self::new(
1184                    ConnectionIdentifier::setup(),
1185                    opts,
1186                    rx,
1187                    Arc::new(fake::Delegate),
1188                    cx,
1189                )
1190            })
1191            .await
1192            .unwrap()
1193            .unwrap()
1194    }
1195}
1196
1197enum ConnectionPoolEntry {
1198    Connecting(Shared<Task<Result<Arc<dyn RemoteConnection>, Arc<anyhow::Error>>>>),
1199    Connected(Weak<dyn RemoteConnection>),
1200}
1201
1202#[derive(Default)]
1203struct ConnectionPool {
1204    connections: HashMap<SshConnectionOptions, ConnectionPoolEntry>,
1205}
1206
1207impl Global for ConnectionPool {}
1208
1209impl ConnectionPool {
1210    pub fn connect(
1211        &mut self,
1212        opts: SshConnectionOptions,
1213        delegate: &Arc<dyn SshClientDelegate>,
1214        cx: &mut App,
1215    ) -> Shared<Task<Result<Arc<dyn RemoteConnection>, Arc<anyhow::Error>>>> {
1216        let connection = self.connections.get(&opts);
1217        match connection {
1218            Some(ConnectionPoolEntry::Connecting(task)) => {
1219                let delegate = delegate.clone();
1220                cx.spawn(|mut cx| async move {
1221                    delegate.set_status(Some("Waiting for existing connection attempt"), &mut cx);
1222                })
1223                .detach();
1224                return task.clone();
1225            }
1226            Some(ConnectionPoolEntry::Connected(ssh)) => {
1227                if let Some(ssh) = ssh.upgrade() {
1228                    if !ssh.has_been_killed() {
1229                        return Task::ready(Ok(ssh)).shared();
1230                    }
1231                }
1232                self.connections.remove(&opts);
1233            }
1234            None => {}
1235        }
1236
1237        let task = cx
1238            .spawn({
1239                let opts = opts.clone();
1240                let delegate = delegate.clone();
1241                |mut cx| async move {
1242                    let connection = SshRemoteConnection::new(opts.clone(), delegate, &mut cx)
1243                        .await
1244                        .map(|connection| Arc::new(connection) as Arc<dyn RemoteConnection>);
1245
1246                    cx.update_global(|pool: &mut Self, _| {
1247                        debug_assert!(matches!(
1248                            pool.connections.get(&opts),
1249                            Some(ConnectionPoolEntry::Connecting(_))
1250                        ));
1251                        match connection {
1252                            Ok(connection) => {
1253                                pool.connections.insert(
1254                                    opts.clone(),
1255                                    ConnectionPoolEntry::Connected(Arc::downgrade(&connection)),
1256                                );
1257                                Ok(connection)
1258                            }
1259                            Err(error) => {
1260                                pool.connections.remove(&opts);
1261                                Err(Arc::new(error))
1262                            }
1263                        }
1264                    })?
1265                }
1266            })
1267            .shared();
1268
1269        self.connections
1270            .insert(opts.clone(), ConnectionPoolEntry::Connecting(task.clone()));
1271        task
1272    }
1273}
1274
1275impl From<SshRemoteClient> for AnyProtoClient {
1276    fn from(client: SshRemoteClient) -> Self {
1277        AnyProtoClient::new(client.client.clone())
1278    }
1279}
1280
1281#[async_trait(?Send)]
1282trait RemoteConnection: Send + Sync {
1283    #[allow(clippy::too_many_arguments)]
1284    fn start_proxy(
1285        &self,
1286        unique_identifier: String,
1287        reconnect: bool,
1288        incoming_tx: UnboundedSender<Envelope>,
1289        outgoing_rx: UnboundedReceiver<Envelope>,
1290        connection_activity_tx: Sender<()>,
1291        delegate: Arc<dyn SshClientDelegate>,
1292        cx: &mut AsyncApp,
1293    ) -> Task<Result<i32>>;
1294    fn upload_directory(&self, src_path: PathBuf, dest_path: PathBuf, cx: &App)
1295        -> Task<Result<()>>;
1296    async fn kill(&self) -> Result<()>;
1297    fn has_been_killed(&self) -> bool;
1298    fn ssh_args(&self) -> Vec<String>;
1299    fn connection_options(&self) -> SshConnectionOptions;
1300
1301    #[cfg(any(test, feature = "test-support"))]
1302    fn simulate_disconnect(&self, _: &AsyncApp) {}
1303}
1304
1305struct SshRemoteConnection {
1306    socket: SshSocket,
1307    master_process: Mutex<Option<Child>>,
1308    remote_binary_path: Option<PathBuf>,
1309    _temp_dir: TempDir,
1310}
1311
1312#[async_trait(?Send)]
1313impl RemoteConnection for SshRemoteConnection {
1314    async fn kill(&self) -> Result<()> {
1315        let Some(mut process) = self.master_process.lock().take() else {
1316            return Ok(());
1317        };
1318        process.kill().ok();
1319        process.status().await?;
1320        Ok(())
1321    }
1322
1323    fn has_been_killed(&self) -> bool {
1324        self.master_process.lock().is_none()
1325    }
1326
1327    fn ssh_args(&self) -> Vec<String> {
1328        self.socket.ssh_args()
1329    }
1330
1331    fn connection_options(&self) -> SshConnectionOptions {
1332        self.socket.connection_options.clone()
1333    }
1334
1335    fn upload_directory(
1336        &self,
1337        src_path: PathBuf,
1338        dest_path: PathBuf,
1339        cx: &App,
1340    ) -> Task<Result<()>> {
1341        let mut command = util::command::new_smol_command("scp");
1342        let output = self
1343            .socket
1344            .ssh_options(&mut command)
1345            .args(
1346                self.socket
1347                    .connection_options
1348                    .port
1349                    .map(|port| vec!["-P".to_string(), port.to_string()])
1350                    .unwrap_or_default(),
1351            )
1352            .arg("-C")
1353            .arg("-r")
1354            .arg(&src_path)
1355            .arg(format!(
1356                "{}:{}",
1357                self.socket.connection_options.scp_url(),
1358                dest_path.display()
1359            ))
1360            .output();
1361
1362        cx.background_executor().spawn(async move {
1363            let output = output.await?;
1364
1365            if !output.status.success() {
1366                return Err(anyhow!(
1367                    "failed to upload directory {} -> {}: {}",
1368                    src_path.display(),
1369                    dest_path.display(),
1370                    String::from_utf8_lossy(&output.stderr)
1371                ));
1372            }
1373
1374            Ok(())
1375        })
1376    }
1377
1378    fn start_proxy(
1379        &self,
1380        unique_identifier: String,
1381        reconnect: bool,
1382        incoming_tx: UnboundedSender<Envelope>,
1383        outgoing_rx: UnboundedReceiver<Envelope>,
1384        connection_activity_tx: Sender<()>,
1385        delegate: Arc<dyn SshClientDelegate>,
1386        cx: &mut AsyncApp,
1387    ) -> Task<Result<i32>> {
1388        delegate.set_status(Some("Starting proxy"), cx);
1389
1390        let Some(remote_binary_path) = self.remote_binary_path.clone() else {
1391            return Task::ready(Err(anyhow!("Remote binary path not set")));
1392        };
1393
1394        let mut start_proxy_command = shell_script!(
1395            "exec {binary_path} proxy --identifier {identifier}",
1396            binary_path = &remote_binary_path.to_string_lossy(),
1397            identifier = &unique_identifier,
1398        );
1399
1400        if let Some(rust_log) = std::env::var("RUST_LOG").ok() {
1401            start_proxy_command = format!(
1402                "RUST_LOG={} {}",
1403                shlex::try_quote(&rust_log).unwrap(),
1404                start_proxy_command
1405            )
1406        }
1407        if let Some(rust_backtrace) = std::env::var("RUST_BACKTRACE").ok() {
1408            start_proxy_command = format!(
1409                "RUST_BACKTRACE={} {}",
1410                shlex::try_quote(&rust_backtrace).unwrap(),
1411                start_proxy_command
1412            )
1413        }
1414        if reconnect {
1415            start_proxy_command.push_str(" --reconnect");
1416        }
1417
1418        let ssh_proxy_process = match self
1419            .socket
1420            .ssh_command("sh", &["-c", &start_proxy_command])
1421            // IMPORTANT: we kill this process when we drop the task that uses it.
1422            .kill_on_drop(true)
1423            .spawn()
1424        {
1425            Ok(process) => process,
1426            Err(error) => {
1427                return Task::ready(Err(anyhow!("failed to spawn remote server: {}", error)))
1428            }
1429        };
1430
1431        Self::multiplex(
1432            ssh_proxy_process,
1433            incoming_tx,
1434            outgoing_rx,
1435            connection_activity_tx,
1436            &cx,
1437        )
1438    }
1439}
1440
1441impl SshRemoteConnection {
1442    #[cfg(not(unix))]
1443    async fn new(
1444        _connection_options: SshConnectionOptions,
1445        _delegate: Arc<dyn SshClientDelegate>,
1446        _cx: &mut AsyncApp,
1447    ) -> Result<Self> {
1448        Err(anyhow!("ssh is not supported on this platform"))
1449    }
1450
1451    #[cfg(unix)]
1452    async fn new(
1453        connection_options: SshConnectionOptions,
1454        delegate: Arc<dyn SshClientDelegate>,
1455        cx: &mut AsyncApp,
1456    ) -> Result<Self> {
1457        use futures::AsyncWriteExt as _;
1458        use futures::{io::BufReader, AsyncBufReadExt as _};
1459        use smol::net::unix::UnixStream;
1460        use smol::{fs::unix::PermissionsExt as _, net::unix::UnixListener};
1461        use util::ResultExt as _;
1462
1463        delegate.set_status(Some("Connecting"), cx);
1464
1465        let url = connection_options.ssh_url();
1466        let temp_dir = tempfile::Builder::new()
1467            .prefix("zed-ssh-session")
1468            .tempdir()?;
1469
1470        // Create a domain socket listener to handle requests from the askpass program.
1471        let askpass_socket = temp_dir.path().join("askpass.sock");
1472        let (askpass_opened_tx, askpass_opened_rx) = oneshot::channel::<()>();
1473        let listener =
1474            UnixListener::bind(&askpass_socket).context("failed to create askpass socket")?;
1475
1476        let (askpass_kill_master_tx, askpass_kill_master_rx) = oneshot::channel::<UnixStream>();
1477        let mut kill_tx = Some(askpass_kill_master_tx);
1478
1479        let askpass_task = cx.spawn({
1480            let delegate = delegate.clone();
1481            |mut cx| async move {
1482                let mut askpass_opened_tx = Some(askpass_opened_tx);
1483
1484                while let Ok((mut stream, _)) = listener.accept().await {
1485                    if let Some(askpass_opened_tx) = askpass_opened_tx.take() {
1486                        askpass_opened_tx.send(()).ok();
1487                    }
1488                    let mut buffer = Vec::new();
1489                    let mut reader = BufReader::new(&mut stream);
1490                    if reader.read_until(b'\0', &mut buffer).await.is_err() {
1491                        buffer.clear();
1492                    }
1493                    let password_prompt = String::from_utf8_lossy(&buffer);
1494                    if let Some(password) = delegate
1495                        .ask_password(password_prompt.to_string(), &mut cx)
1496                        .await
1497                        .context("failed to get ssh password")
1498                        .and_then(|p| p)
1499                        .log_err()
1500                    {
1501                        stream.write_all(password.as_bytes()).await.log_err();
1502                    } else {
1503                        if let Some(kill_tx) = kill_tx.take() {
1504                            kill_tx.send(stream).log_err();
1505                            break;
1506                        }
1507                    }
1508                }
1509            }
1510        });
1511
1512        anyhow::ensure!(
1513            which::which("nc").is_ok(),
1514            "Cannot find `nc` command (netcat), which is required to connect over SSH."
1515        );
1516
1517        // Create an askpass script that communicates back to this process.
1518        let askpass_script = format!(
1519            "{shebang}\n{print_args} | {nc} -U {askpass_socket} 2> /dev/null \n",
1520            // on macOS `brew install netcat` provides the GNU netcat implementation
1521            // which does not support -U.
1522            nc = if cfg!(target_os = "macos") {
1523                "/usr/bin/nc"
1524            } else {
1525                "nc"
1526            },
1527            askpass_socket = askpass_socket.display(),
1528            print_args = "printf '%s\\0' \"$@\"",
1529            shebang = "#!/bin/sh",
1530        );
1531        let askpass_script_path = temp_dir.path().join("askpass.sh");
1532        fs::write(&askpass_script_path, askpass_script).await?;
1533        fs::set_permissions(&askpass_script_path, std::fs::Permissions::from_mode(0o755)).await?;
1534
1535        // Start the master SSH process, which does not do anything except for establish
1536        // the connection and keep it open, allowing other ssh commands to reuse it
1537        // via a control socket.
1538        let socket_path = temp_dir.path().join("ssh.sock");
1539
1540        let mut master_process = process::Command::new("ssh")
1541            .stdin(Stdio::null())
1542            .stdout(Stdio::piped())
1543            .stderr(Stdio::piped())
1544            .env("SSH_ASKPASS_REQUIRE", "force")
1545            .env("SSH_ASKPASS", &askpass_script_path)
1546            .args(connection_options.additional_args())
1547            .args([
1548                "-N",
1549                "-o",
1550                "ControlPersist=no",
1551                "-o",
1552                "ControlMaster=yes",
1553                "-o",
1554            ])
1555            .arg(format!("ControlPath={}", socket_path.display()))
1556            .arg(&url)
1557            .kill_on_drop(true)
1558            .spawn()?;
1559
1560        // Wait for this ssh process to close its stdout, indicating that authentication
1561        // has completed.
1562        let mut stdout = master_process.stdout.take().unwrap();
1563        let mut output = Vec::new();
1564        let connection_timeout = Duration::from_secs(10);
1565
1566        let result = select_biased! {
1567            _ = askpass_opened_rx.fuse() => {
1568                select_biased! {
1569                    stream = askpass_kill_master_rx.fuse() => {
1570                        master_process.kill().ok();
1571                        drop(stream);
1572                        Err(anyhow!("SSH connection canceled"))
1573                    }
1574                    // If the askpass script has opened, that means the user is typing
1575                    // their password, in which case we don't want to timeout anymore,
1576                    // since we know a connection has been established.
1577                    result = stdout.read_to_end(&mut output).fuse() => {
1578                        result?;
1579                        Ok(())
1580                    }
1581                }
1582            }
1583            _ = stdout.read_to_end(&mut output).fuse() => {
1584                Ok(())
1585            }
1586            _ = futures::FutureExt::fuse(smol::Timer::after(connection_timeout)) => {
1587                Err(anyhow!("Exceeded {:?} timeout trying to connect to host", connection_timeout))
1588            }
1589        };
1590
1591        if let Err(e) = result {
1592            return Err(e.context("Failed to connect to host"));
1593        }
1594
1595        drop(askpass_task);
1596
1597        if master_process.try_status()?.is_some() {
1598            output.clear();
1599            let mut stderr = master_process.stderr.take().unwrap();
1600            stderr.read_to_end(&mut output).await?;
1601
1602            let error_message = format!(
1603                "failed to connect: {}",
1604                String::from_utf8_lossy(&output).trim()
1605            );
1606            Err(anyhow!(error_message))?;
1607        }
1608
1609        let socket = SshSocket {
1610            connection_options,
1611            socket_path,
1612        };
1613
1614        let mut this = Self {
1615            socket,
1616            master_process: Mutex::new(Some(master_process)),
1617            _temp_dir: temp_dir,
1618            remote_binary_path: None,
1619        };
1620
1621        let (release_channel, version, commit) = cx.update(|cx| {
1622            (
1623                ReleaseChannel::global(cx),
1624                AppVersion::global(cx),
1625                AppCommitSha::try_global(cx),
1626            )
1627        })?;
1628        this.remote_binary_path = Some(
1629            this.ensure_server_binary(&delegate, release_channel, version, commit, cx)
1630                .await?,
1631        );
1632
1633        Ok(this)
1634    }
1635
1636    async fn platform(&self) -> Result<SshPlatform> {
1637        let uname = self.socket.run_command("uname", &["-sm"]).await?;
1638        let Some((os, arch)) = uname.split_once(" ") else {
1639            Err(anyhow!("unknown uname: {uname:?}"))?
1640        };
1641
1642        let os = match os.trim() {
1643            "Darwin" => "macos",
1644            "Linux" => "linux",
1645            _ => Err(anyhow!(
1646                "Prebuilt remote servers are not yet available for {os:?}. See https://zed.dev/docs/remote-development"
1647            ))?,
1648        };
1649        // exclude armv5,6,7 as they are 32-bit.
1650        let arch = if arch.starts_with("armv8")
1651            || arch.starts_with("armv9")
1652            || arch.starts_with("arm64")
1653            || arch.starts_with("aarch64")
1654        {
1655            "aarch64"
1656        } else if arch.starts_with("x86") {
1657            "x86_64"
1658        } else {
1659            Err(anyhow!(
1660                "Prebuilt remote servers are not yet available for {arch:?}. See https://zed.dev/docs/remote-development"
1661            ))?
1662        };
1663
1664        Ok(SshPlatform { os, arch })
1665    }
1666
1667    fn multiplex(
1668        mut ssh_proxy_process: Child,
1669        incoming_tx: UnboundedSender<Envelope>,
1670        mut outgoing_rx: UnboundedReceiver<Envelope>,
1671        mut connection_activity_tx: Sender<()>,
1672        cx: &AsyncApp,
1673    ) -> Task<Result<i32>> {
1674        let mut child_stderr = ssh_proxy_process.stderr.take().unwrap();
1675        let mut child_stdout = ssh_proxy_process.stdout.take().unwrap();
1676        let mut child_stdin = ssh_proxy_process.stdin.take().unwrap();
1677
1678        let mut stdin_buffer = Vec::new();
1679        let mut stdout_buffer = Vec::new();
1680        let mut stderr_buffer = Vec::new();
1681        let mut stderr_offset = 0;
1682
1683        let stdin_task = cx.background_executor().spawn(async move {
1684            while let Some(outgoing) = outgoing_rx.next().await {
1685                write_message(&mut child_stdin, &mut stdin_buffer, outgoing).await?;
1686            }
1687            anyhow::Ok(())
1688        });
1689
1690        let stdout_task = cx.background_executor().spawn({
1691            let mut connection_activity_tx = connection_activity_tx.clone();
1692            async move {
1693                loop {
1694                    stdout_buffer.resize(MESSAGE_LEN_SIZE, 0);
1695                    let len = child_stdout.read(&mut stdout_buffer).await?;
1696
1697                    if len == 0 {
1698                        return anyhow::Ok(());
1699                    }
1700
1701                    if len < MESSAGE_LEN_SIZE {
1702                        child_stdout.read_exact(&mut stdout_buffer[len..]).await?;
1703                    }
1704
1705                    let message_len = message_len_from_buffer(&stdout_buffer);
1706                    let envelope =
1707                        read_message_with_len(&mut child_stdout, &mut stdout_buffer, message_len)
1708                            .await?;
1709                    connection_activity_tx.try_send(()).ok();
1710                    incoming_tx.unbounded_send(envelope).ok();
1711                }
1712            }
1713        });
1714
1715        let stderr_task: Task<anyhow::Result<()>> = cx.background_executor().spawn(async move {
1716            loop {
1717                stderr_buffer.resize(stderr_offset + 1024, 0);
1718
1719                let len = child_stderr
1720                    .read(&mut stderr_buffer[stderr_offset..])
1721                    .await?;
1722                if len == 0 {
1723                    return anyhow::Ok(());
1724                }
1725
1726                stderr_offset += len;
1727                let mut start_ix = 0;
1728                while let Some(ix) = stderr_buffer[start_ix..stderr_offset]
1729                    .iter()
1730                    .position(|b| b == &b'\n')
1731                {
1732                    let line_ix = start_ix + ix;
1733                    let content = &stderr_buffer[start_ix..line_ix];
1734                    start_ix = line_ix + 1;
1735                    if let Ok(record) = serde_json::from_slice::<LogRecord>(content) {
1736                        record.log(log::logger())
1737                    } else {
1738                        eprintln!("(remote) {}", String::from_utf8_lossy(content));
1739                    }
1740                }
1741                stderr_buffer.drain(0..start_ix);
1742                stderr_offset -= start_ix;
1743
1744                connection_activity_tx.try_send(()).ok();
1745            }
1746        });
1747
1748        cx.spawn(|_| async move {
1749            let result = futures::select! {
1750                result = stdin_task.fuse() => {
1751                    result.context("stdin")
1752                }
1753                result = stdout_task.fuse() => {
1754                    result.context("stdout")
1755                }
1756                result = stderr_task.fuse() => {
1757                    result.context("stderr")
1758                }
1759            };
1760
1761            let status = ssh_proxy_process.status().await?.code().unwrap_or(1);
1762            match result {
1763                Ok(_) => Ok(status),
1764                Err(error) => Err(error),
1765            }
1766        })
1767    }
1768
1769    #[allow(unused)]
1770    async fn ensure_server_binary(
1771        &self,
1772        delegate: &Arc<dyn SshClientDelegate>,
1773        release_channel: ReleaseChannel,
1774        version: SemanticVersion,
1775        commit: Option<AppCommitSha>,
1776        cx: &mut AsyncApp,
1777    ) -> Result<PathBuf> {
1778        let version_str = match release_channel {
1779            ReleaseChannel::Nightly => {
1780                let commit = commit.map(|s| s.0.to_string()).unwrap_or_default();
1781
1782                format!("{}-{}", version, commit)
1783            }
1784            ReleaseChannel::Dev => "build".to_string(),
1785            _ => version.to_string(),
1786        };
1787        let binary_name = format!(
1788            "zed-remote-server-{}-{}",
1789            release_channel.dev_name(),
1790            version_str
1791        );
1792        let dst_path = paths::remote_server_dir_relative().join(binary_name);
1793        let tmp_path_gz = PathBuf::from(format!(
1794            "{}-download-{}.gz",
1795            dst_path.to_string_lossy(),
1796            std::process::id()
1797        ));
1798
1799        #[cfg(debug_assertions)]
1800        if std::env::var("ZED_BUILD_REMOTE_SERVER").is_ok() {
1801            let src_path = self
1802                .build_local(self.platform().await?, delegate, cx)
1803                .await?;
1804            self.upload_local_server_binary(&src_path, &tmp_path_gz, delegate, cx)
1805                .await?;
1806            self.extract_server_binary(&dst_path, &tmp_path_gz, delegate, cx)
1807                .await?;
1808            return Ok(dst_path);
1809        }
1810
1811        if self
1812            .socket
1813            .run_command(&dst_path.to_string_lossy(), &["version"])
1814            .await
1815            .is_ok()
1816        {
1817            return Ok(dst_path);
1818        }
1819
1820        let wanted_version = cx.update(|cx| match release_channel {
1821            ReleaseChannel::Nightly => Ok(None),
1822            ReleaseChannel::Dev => {
1823                anyhow::bail!(
1824                    "ZED_BUILD_REMOTE_SERVER is not set and no remote server exists at ({:?})",
1825                    dst_path
1826                )
1827            }
1828            _ => Ok(Some(AppVersion::global(cx))),
1829        })??;
1830
1831        let platform = self.platform().await?;
1832
1833        if !self.socket.connection_options.upload_binary_over_ssh {
1834            if let Some((url, body)) = delegate
1835                .get_download_params(platform, release_channel, wanted_version, cx)
1836                .await?
1837            {
1838                match self
1839                    .download_binary_on_server(&url, &body, &tmp_path_gz, delegate, cx)
1840                    .await
1841                {
1842                    Ok(_) => {
1843                        self.extract_server_binary(&dst_path, &tmp_path_gz, delegate, cx)
1844                            .await?;
1845                        return Ok(dst_path);
1846                    }
1847                    Err(e) => {
1848                        log::error!(
1849                            "Failed to download binary on server, attempting to upload server: {}",
1850                            e
1851                        )
1852                    }
1853                }
1854            }
1855        }
1856
1857        let src_path = delegate
1858            .download_server_binary_locally(platform, release_channel, wanted_version, cx)
1859            .await?;
1860        self.upload_local_server_binary(&src_path, &tmp_path_gz, delegate, cx)
1861            .await?;
1862        self.extract_server_binary(&dst_path, &tmp_path_gz, delegate, cx)
1863            .await?;
1864        return Ok(dst_path);
1865    }
1866
1867    async fn download_binary_on_server(
1868        &self,
1869        url: &str,
1870        body: &str,
1871        tmp_path_gz: &Path,
1872        delegate: &Arc<dyn SshClientDelegate>,
1873        cx: &mut AsyncApp,
1874    ) -> Result<()> {
1875        if let Some(parent) = tmp_path_gz.parent() {
1876            self.socket
1877                .run_command("mkdir", &["-p", &parent.to_string_lossy()])
1878                .await?;
1879        }
1880
1881        delegate.set_status(Some("Downloading remote development server on host"), cx);
1882
1883        match self
1884            .socket
1885            .run_command(
1886                "curl",
1887                &[
1888                    "-f",
1889                    "-L",
1890                    "-X",
1891                    "GET",
1892                    "-H",
1893                    "Content-Type: application/json",
1894                    "-d",
1895                    &body,
1896                    &url,
1897                    "-o",
1898                    &tmp_path_gz.to_string_lossy(),
1899                ],
1900            )
1901            .await
1902        {
1903            Ok(_) => {}
1904            Err(e) => {
1905                if self.socket.run_command("which", &["curl"]).await.is_ok() {
1906                    return Err(e);
1907                }
1908
1909                match self
1910                    .socket
1911                    .run_command(
1912                        "wget",
1913                        &[
1914                            "--max-redirect=5",
1915                            "--method=GET",
1916                            "--header=Content-Type: application/json",
1917                            "--body-data",
1918                            &body,
1919                            &url,
1920                            "-O",
1921                            &tmp_path_gz.to_string_lossy(),
1922                        ],
1923                    )
1924                    .await
1925                {
1926                    Ok(_) => {}
1927                    Err(e) => {
1928                        if self.socket.run_command("which", &["wget"]).await.is_ok() {
1929                            return Err(e);
1930                        } else {
1931                            anyhow::bail!("Neither curl nor wget is available");
1932                        }
1933                    }
1934                }
1935            }
1936        }
1937
1938        Ok(())
1939    }
1940
1941    async fn upload_local_server_binary(
1942        &self,
1943        src_path: &Path,
1944        tmp_path_gz: &Path,
1945        delegate: &Arc<dyn SshClientDelegate>,
1946        cx: &mut AsyncApp,
1947    ) -> Result<()> {
1948        if let Some(parent) = tmp_path_gz.parent() {
1949            self.socket
1950                .run_command("mkdir", &["-p", &parent.to_string_lossy()])
1951                .await?;
1952        }
1953
1954        let src_stat = fs::metadata(&src_path).await?;
1955        let size = src_stat.len();
1956
1957        let t0 = Instant::now();
1958        delegate.set_status(Some("Uploading remote development server"), cx);
1959        log::info!(
1960            "uploading remote development server to {:?} ({}kb)",
1961            tmp_path_gz,
1962            size / 1024
1963        );
1964        self.upload_file(&src_path, &tmp_path_gz)
1965            .await
1966            .context("failed to upload server binary")?;
1967        log::info!("uploaded remote development server in {:?}", t0.elapsed());
1968        Ok(())
1969    }
1970
1971    async fn extract_server_binary(
1972        &self,
1973        dst_path: &Path,
1974        tmp_path_gz: &Path,
1975        delegate: &Arc<dyn SshClientDelegate>,
1976        cx: &mut AsyncApp,
1977    ) -> Result<()> {
1978        delegate.set_status(Some("Extracting remote development server"), cx);
1979        let server_mode = 0o755;
1980
1981        let script = shell_script!(
1982            "gunzip -f {tmp_path_gz} && chmod {server_mode} {tmp_path} && mv {tmp_path} {dst_path}",
1983            tmp_path_gz = &tmp_path_gz.to_string_lossy(),
1984            tmp_path = &tmp_path_gz.to_string_lossy().strip_suffix(".gz").unwrap(),
1985            server_mode = &format!("{:o}", server_mode),
1986            dst_path = &dst_path.to_string_lossy()
1987        );
1988        self.socket.run_command("sh", &["-c", &script]).await?;
1989        Ok(())
1990    }
1991
1992    async fn upload_file(&self, src_path: &Path, dest_path: &Path) -> Result<()> {
1993        log::debug!("uploading file {:?} to {:?}", src_path, dest_path);
1994        let mut command = util::command::new_smol_command("scp");
1995        let output = self
1996            .socket
1997            .ssh_options(&mut command)
1998            .args(
1999                self.socket
2000                    .connection_options
2001                    .port
2002                    .map(|port| vec!["-P".to_string(), port.to_string()])
2003                    .unwrap_or_default(),
2004            )
2005            .arg(src_path)
2006            .arg(format!(
2007                "{}:{}",
2008                self.socket.connection_options.scp_url(),
2009                dest_path.display()
2010            ))
2011            .output()
2012            .await?;
2013
2014        if output.status.success() {
2015            Ok(())
2016        } else {
2017            Err(anyhow!(
2018                "failed to upload file {} -> {}: {}",
2019                src_path.display(),
2020                dest_path.display(),
2021                String::from_utf8_lossy(&output.stderr)
2022            ))
2023        }
2024    }
2025
2026    #[cfg(debug_assertions)]
2027    async fn build_local(
2028        &self,
2029        platform: SshPlatform,
2030        delegate: &Arc<dyn SshClientDelegate>,
2031        cx: &mut AsyncApp,
2032    ) -> Result<PathBuf> {
2033        use smol::process::{Command, Stdio};
2034
2035        async fn run_cmd(command: &mut Command) -> Result<()> {
2036            let output = command
2037                .kill_on_drop(true)
2038                .stderr(Stdio::inherit())
2039                .output()
2040                .await?;
2041            if !output.status.success() {
2042                Err(anyhow!("Failed to run command: {:?}", command))?;
2043            }
2044            Ok(())
2045        }
2046
2047        if platform.arch == std::env::consts::ARCH && platform.os == std::env::consts::OS {
2048            delegate.set_status(Some("Building remote server binary from source"), cx);
2049            log::info!("building remote server binary from source");
2050            run_cmd(Command::new("cargo").args([
2051                "build",
2052                "--package",
2053                "remote_server",
2054                "--features",
2055                "debug-embed",
2056                "--target-dir",
2057                "target/remote_server",
2058            ]))
2059            .await?;
2060
2061            delegate.set_status(Some("Compressing binary"), cx);
2062
2063            run_cmd(Command::new("gzip").args([
2064                "-9",
2065                "-f",
2066                "target/remote_server/debug/remote_server",
2067            ]))
2068            .await?;
2069
2070            let path = std::env::current_dir()?.join("target/remote_server/debug/remote_server.gz");
2071            return Ok(path);
2072        }
2073        let Some(triple) = platform.triple() else {
2074            anyhow::bail!("can't cross compile for: {:?}", platform);
2075        };
2076        smol::fs::create_dir_all("target/remote_server").await?;
2077
2078        delegate.set_status(Some("Installing cross.rs for cross-compilation"), cx);
2079        log::info!("installing cross");
2080        run_cmd(Command::new("cargo").args([
2081            "install",
2082            "cross",
2083            "--git",
2084            "https://github.com/cross-rs/cross",
2085        ]))
2086        .await?;
2087
2088        delegate.set_status(
2089            Some(&format!(
2090                "Building remote server binary from source for {} with Docker",
2091                &triple
2092            )),
2093            cx,
2094        );
2095        log::info!("building remote server binary from source for {}", &triple);
2096        run_cmd(
2097            Command::new("cross")
2098                .args([
2099                    "build",
2100                    "--package",
2101                    "remote_server",
2102                    "--features",
2103                    "debug-embed",
2104                    "--target-dir",
2105                    "target/remote_server",
2106                    "--target",
2107                    &triple,
2108                ])
2109                .env(
2110                    "CROSS_CONTAINER_OPTS",
2111                    "--mount type=bind,src=./target,dst=/app/target",
2112                ),
2113        )
2114        .await?;
2115
2116        delegate.set_status(Some("Compressing binary"), cx);
2117
2118        run_cmd(Command::new("gzip").args([
2119            "-9",
2120            "-f",
2121            &format!("target/remote_server/{}/debug/remote_server", triple),
2122        ]))
2123        .await?;
2124
2125        let path = std::env::current_dir()?.join(format!(
2126            "target/remote_server/{}/debug/remote_server.gz",
2127            triple
2128        ));
2129
2130        return Ok(path);
2131    }
2132}
2133
2134type ResponseChannels = Mutex<HashMap<MessageId, oneshot::Sender<(Envelope, oneshot::Sender<()>)>>>;
2135
2136pub struct ChannelClient {
2137    next_message_id: AtomicU32,
2138    outgoing_tx: Mutex<mpsc::UnboundedSender<Envelope>>,
2139    buffer: Mutex<VecDeque<Envelope>>,
2140    response_channels: ResponseChannels,
2141    message_handlers: Mutex<ProtoMessageHandlerSet>,
2142    max_received: AtomicU32,
2143    name: &'static str,
2144    task: Mutex<Task<Result<()>>>,
2145}
2146
2147impl ChannelClient {
2148    pub fn new(
2149        incoming_rx: mpsc::UnboundedReceiver<Envelope>,
2150        outgoing_tx: mpsc::UnboundedSender<Envelope>,
2151        cx: &App,
2152        name: &'static str,
2153    ) -> Arc<Self> {
2154        Arc::new_cyclic(|this| Self {
2155            outgoing_tx: Mutex::new(outgoing_tx),
2156            next_message_id: AtomicU32::new(0),
2157            max_received: AtomicU32::new(0),
2158            response_channels: ResponseChannels::default(),
2159            message_handlers: Default::default(),
2160            buffer: Mutex::new(VecDeque::new()),
2161            name,
2162            task: Mutex::new(Self::start_handling_messages(
2163                this.clone(),
2164                incoming_rx,
2165                &cx.to_async(),
2166            )),
2167        })
2168    }
2169
2170    fn start_handling_messages(
2171        this: Weak<Self>,
2172        mut incoming_rx: mpsc::UnboundedReceiver<Envelope>,
2173        cx: &AsyncApp,
2174    ) -> Task<Result<()>> {
2175        cx.spawn(|cx| async move {
2176            let peer_id = PeerId { owner_id: 0, id: 0 };
2177            while let Some(incoming) = incoming_rx.next().await {
2178                let Some(this) = this.upgrade() else {
2179                    return anyhow::Ok(());
2180                };
2181                if let Some(ack_id) = incoming.ack_id {
2182                    let mut buffer = this.buffer.lock();
2183                    while buffer.front().is_some_and(|msg| msg.id <= ack_id) {
2184                        buffer.pop_front();
2185                    }
2186                }
2187                if let Some(proto::envelope::Payload::FlushBufferedMessages(_)) = &incoming.payload
2188                {
2189                    log::debug!(
2190                        "{}:ssh message received. name:FlushBufferedMessages",
2191                        this.name
2192                    );
2193                    {
2194                        let buffer = this.buffer.lock();
2195                        for envelope in buffer.iter() {
2196                            this.outgoing_tx
2197                                .lock()
2198                                .unbounded_send(envelope.clone())
2199                                .ok();
2200                        }
2201                    }
2202                    let mut envelope = proto::Ack {}.into_envelope(0, Some(incoming.id), None);
2203                    envelope.id = this.next_message_id.fetch_add(1, SeqCst);
2204                    this.outgoing_tx.lock().unbounded_send(envelope).ok();
2205                    continue;
2206                }
2207
2208                this.max_received.store(incoming.id, SeqCst);
2209
2210                if let Some(request_id) = incoming.responding_to {
2211                    let request_id = MessageId(request_id);
2212                    let sender = this.response_channels.lock().remove(&request_id);
2213                    if let Some(sender) = sender {
2214                        let (tx, rx) = oneshot::channel();
2215                        if incoming.payload.is_some() {
2216                            sender.send((incoming, tx)).ok();
2217                        }
2218                        rx.await.ok();
2219                    }
2220                } else if let Some(envelope) =
2221                    build_typed_envelope(peer_id, Instant::now(), incoming)
2222                {
2223                    let type_name = envelope.payload_type_name();
2224                    if let Some(future) = ProtoMessageHandlerSet::handle_message(
2225                        &this.message_handlers,
2226                        envelope,
2227                        this.clone().into(),
2228                        cx.clone(),
2229                    ) {
2230                        log::debug!("{}:ssh message received. name:{type_name}", this.name);
2231                        cx.foreground_executor()
2232                            .spawn(async move {
2233                                match future.await {
2234                                    Ok(_) => {
2235                                        log::debug!(
2236                                            "{}:ssh message handled. name:{type_name}",
2237                                            this.name
2238                                        );
2239                                    }
2240                                    Err(error) => {
2241                                        log::error!(
2242                                            "{}:error handling message. type:{}, error:{}",
2243                                            this.name,
2244                                            type_name,
2245                                            format!("{error:#}").lines().fold(
2246                                                String::new(),
2247                                                |mut message, line| {
2248                                                    if !message.is_empty() {
2249                                                        message.push(' ');
2250                                                    }
2251                                                    message.push_str(line);
2252                                                    message
2253                                                }
2254                                            )
2255                                        );
2256                                    }
2257                                }
2258                            })
2259                            .detach()
2260                    } else {
2261                        log::error!("{}:unhandled ssh message name:{type_name}", this.name);
2262                    }
2263                }
2264            }
2265            anyhow::Ok(())
2266        })
2267    }
2268
2269    pub fn reconnect(
2270        self: &Arc<Self>,
2271        incoming_rx: UnboundedReceiver<Envelope>,
2272        outgoing_tx: UnboundedSender<Envelope>,
2273        cx: &AsyncApp,
2274    ) {
2275        *self.outgoing_tx.lock() = outgoing_tx;
2276        *self.task.lock() = Self::start_handling_messages(Arc::downgrade(self), incoming_rx, cx);
2277    }
2278
2279    pub fn subscribe_to_entity<E: 'static>(&self, remote_id: u64, entity: &Entity<E>) {
2280        let id = (TypeId::of::<E>(), remote_id);
2281
2282        let mut message_handlers = self.message_handlers.lock();
2283        if message_handlers
2284            .entities_by_type_and_remote_id
2285            .contains_key(&id)
2286        {
2287            panic!("already subscribed to entity");
2288        }
2289
2290        message_handlers.entities_by_type_and_remote_id.insert(
2291            id,
2292            EntityMessageSubscriber::Entity {
2293                handle: entity.downgrade().into(),
2294            },
2295        );
2296    }
2297
2298    pub fn request<T: RequestMessage>(
2299        &self,
2300        payload: T,
2301    ) -> impl 'static + Future<Output = Result<T::Response>> {
2302        self.request_internal(payload, true)
2303    }
2304
2305    fn request_internal<T: RequestMessage>(
2306        &self,
2307        payload: T,
2308        use_buffer: bool,
2309    ) -> impl 'static + Future<Output = Result<T::Response>> {
2310        log::debug!("ssh request start. name:{}", T::NAME);
2311        let response =
2312            self.request_dynamic(payload.into_envelope(0, None, None), T::NAME, use_buffer);
2313        async move {
2314            let response = response.await?;
2315            log::debug!("ssh request finish. name:{}", T::NAME);
2316            T::Response::from_envelope(response)
2317                .ok_or_else(|| anyhow!("received a response of the wrong type"))
2318        }
2319    }
2320
2321    pub async fn resync(&self, timeout: Duration) -> Result<()> {
2322        smol::future::or(
2323            async {
2324                self.request_internal(proto::FlushBufferedMessages {}, false)
2325                    .await?;
2326
2327                for envelope in self.buffer.lock().iter() {
2328                    self.outgoing_tx
2329                        .lock()
2330                        .unbounded_send(envelope.clone())
2331                        .ok();
2332                }
2333                Ok(())
2334            },
2335            async {
2336                smol::Timer::after(timeout).await;
2337                Err(anyhow!("Timeout detected"))
2338            },
2339        )
2340        .await
2341    }
2342
2343    pub async fn ping(&self, timeout: Duration) -> Result<()> {
2344        smol::future::or(
2345            async {
2346                self.request(proto::Ping {}).await?;
2347                Ok(())
2348            },
2349            async {
2350                smol::Timer::after(timeout).await;
2351                Err(anyhow!("Timeout detected"))
2352            },
2353        )
2354        .await
2355    }
2356
2357    pub fn send<T: EnvelopedMessage>(&self, payload: T) -> Result<()> {
2358        log::debug!("ssh send name:{}", T::NAME);
2359        self.send_dynamic(payload.into_envelope(0, None, None))
2360    }
2361
2362    fn request_dynamic(
2363        &self,
2364        mut envelope: proto::Envelope,
2365        type_name: &'static str,
2366        use_buffer: bool,
2367    ) -> impl 'static + Future<Output = Result<proto::Envelope>> {
2368        envelope.id = self.next_message_id.fetch_add(1, SeqCst);
2369        let (tx, rx) = oneshot::channel();
2370        let mut response_channels_lock = self.response_channels.lock();
2371        response_channels_lock.insert(MessageId(envelope.id), tx);
2372        drop(response_channels_lock);
2373
2374        let result = if use_buffer {
2375            self.send_buffered(envelope)
2376        } else {
2377            self.send_unbuffered(envelope)
2378        };
2379        async move {
2380            if let Err(error) = &result {
2381                log::error!("failed to send message: {}", error);
2382                return Err(anyhow!("failed to send message: {}", error));
2383            }
2384
2385            let response = rx.await.context("connection lost")?.0;
2386            if let Some(proto::envelope::Payload::Error(error)) = &response.payload {
2387                return Err(RpcError::from_proto(error, type_name));
2388            }
2389            Ok(response)
2390        }
2391    }
2392
2393    pub fn send_dynamic(&self, mut envelope: proto::Envelope) -> Result<()> {
2394        envelope.id = self.next_message_id.fetch_add(1, SeqCst);
2395        self.send_buffered(envelope)
2396    }
2397
2398    fn send_buffered(&self, mut envelope: proto::Envelope) -> Result<()> {
2399        envelope.ack_id = Some(self.max_received.load(SeqCst));
2400        self.buffer.lock().push_back(envelope.clone());
2401        // ignore errors on send (happen while we're reconnecting)
2402        // assume that the global "disconnected" overlay is sufficient.
2403        self.outgoing_tx.lock().unbounded_send(envelope).ok();
2404        Ok(())
2405    }
2406
2407    fn send_unbuffered(&self, mut envelope: proto::Envelope) -> Result<()> {
2408        envelope.ack_id = Some(self.max_received.load(SeqCst));
2409        self.outgoing_tx.lock().unbounded_send(envelope).ok();
2410        Ok(())
2411    }
2412}
2413
2414impl ProtoClient for ChannelClient {
2415    fn request(
2416        &self,
2417        envelope: proto::Envelope,
2418        request_type: &'static str,
2419    ) -> BoxFuture<'static, Result<proto::Envelope>> {
2420        self.request_dynamic(envelope, request_type, true).boxed()
2421    }
2422
2423    fn send(&self, envelope: proto::Envelope, _message_type: &'static str) -> Result<()> {
2424        self.send_dynamic(envelope)
2425    }
2426
2427    fn send_response(&self, envelope: Envelope, _message_type: &'static str) -> anyhow::Result<()> {
2428        self.send_dynamic(envelope)
2429    }
2430
2431    fn message_handler_set(&self) -> &Mutex<ProtoMessageHandlerSet> {
2432        &self.message_handlers
2433    }
2434
2435    fn is_via_collab(&self) -> bool {
2436        false
2437    }
2438}
2439
2440#[cfg(any(test, feature = "test-support"))]
2441mod fake {
2442    use std::{path::PathBuf, sync::Arc};
2443
2444    use anyhow::Result;
2445    use async_trait::async_trait;
2446    use futures::{
2447        channel::{
2448            mpsc::{self, Sender},
2449            oneshot,
2450        },
2451        select_biased, FutureExt, SinkExt, StreamExt,
2452    };
2453    use gpui::{App, AsyncApp, SemanticVersion, Task, TestAppContext};
2454    use release_channel::ReleaseChannel;
2455    use rpc::proto::Envelope;
2456
2457    use super::{
2458        ChannelClient, RemoteConnection, SshClientDelegate, SshConnectionOptions, SshPlatform,
2459    };
2460
2461    pub(super) struct FakeRemoteConnection {
2462        pub(super) connection_options: SshConnectionOptions,
2463        pub(super) server_channel: Arc<ChannelClient>,
2464        pub(super) server_cx: SendableCx,
2465    }
2466
2467    pub(super) struct SendableCx(AsyncApp);
2468    impl SendableCx {
2469        // SAFETY: When run in test mode, GPUI is always single threaded.
2470        pub(super) fn new(cx: &TestAppContext) -> Self {
2471            Self(cx.to_async())
2472        }
2473
2474        // SAFETY: Enforce that we're on the main thread by requiring a valid AsyncApp
2475        fn get(&self, _: &AsyncApp) -> AsyncApp {
2476            self.0.clone()
2477        }
2478    }
2479
2480    // SAFETY: There is no way to access a SendableCx from a different thread, see [`SendableCx::new`] and [`SendableCx::get`]
2481    unsafe impl Send for SendableCx {}
2482    unsafe impl Sync for SendableCx {}
2483
2484    #[async_trait(?Send)]
2485    impl RemoteConnection for FakeRemoteConnection {
2486        async fn kill(&self) -> Result<()> {
2487            Ok(())
2488        }
2489
2490        fn has_been_killed(&self) -> bool {
2491            false
2492        }
2493
2494        fn ssh_args(&self) -> Vec<String> {
2495            Vec::new()
2496        }
2497        fn upload_directory(
2498            &self,
2499            _src_path: PathBuf,
2500            _dest_path: PathBuf,
2501            _cx: &App,
2502        ) -> Task<Result<()>> {
2503            unreachable!()
2504        }
2505
2506        fn connection_options(&self) -> SshConnectionOptions {
2507            self.connection_options.clone()
2508        }
2509
2510        fn simulate_disconnect(&self, cx: &AsyncApp) {
2511            let (outgoing_tx, _) = mpsc::unbounded::<Envelope>();
2512            let (_, incoming_rx) = mpsc::unbounded::<Envelope>();
2513            self.server_channel
2514                .reconnect(incoming_rx, outgoing_tx, &self.server_cx.get(&cx));
2515        }
2516
2517        fn start_proxy(
2518            &self,
2519
2520            _unique_identifier: String,
2521            _reconnect: bool,
2522            mut client_incoming_tx: mpsc::UnboundedSender<Envelope>,
2523            mut client_outgoing_rx: mpsc::UnboundedReceiver<Envelope>,
2524            mut connection_activity_tx: Sender<()>,
2525            _delegate: Arc<dyn SshClientDelegate>,
2526            cx: &mut AsyncApp,
2527        ) -> Task<Result<i32>> {
2528            let (mut server_incoming_tx, server_incoming_rx) = mpsc::unbounded::<Envelope>();
2529            let (server_outgoing_tx, mut server_outgoing_rx) = mpsc::unbounded::<Envelope>();
2530
2531            self.server_channel.reconnect(
2532                server_incoming_rx,
2533                server_outgoing_tx,
2534                &self.server_cx.get(cx),
2535            );
2536
2537            cx.background_executor().spawn(async move {
2538                loop {
2539                    select_biased! {
2540                        server_to_client = server_outgoing_rx.next().fuse() => {
2541                            let Some(server_to_client) = server_to_client else {
2542                                return Ok(1)
2543                            };
2544                            connection_activity_tx.try_send(()).ok();
2545                            client_incoming_tx.send(server_to_client).await.ok();
2546                        }
2547                        client_to_server = client_outgoing_rx.next().fuse() => {
2548                            let Some(client_to_server) = client_to_server else {
2549                                return Ok(1)
2550                            };
2551                            server_incoming_tx.send(client_to_server).await.ok();
2552                        }
2553                    }
2554                }
2555            })
2556        }
2557    }
2558
2559    pub(super) struct Delegate;
2560
2561    impl SshClientDelegate for Delegate {
2562        fn ask_password(&self, _: String, _: &mut AsyncApp) -> oneshot::Receiver<Result<String>> {
2563            unreachable!()
2564        }
2565
2566        fn download_server_binary_locally(
2567            &self,
2568            _: SshPlatform,
2569            _: ReleaseChannel,
2570            _: Option<SemanticVersion>,
2571            _: &mut AsyncApp,
2572        ) -> Task<Result<PathBuf>> {
2573            unreachable!()
2574        }
2575
2576        fn get_download_params(
2577            &self,
2578            _platform: SshPlatform,
2579            _release_channel: ReleaseChannel,
2580            _version: Option<SemanticVersion>,
2581            _cx: &mut AsyncApp,
2582        ) -> Task<Result<Option<(String, String)>>> {
2583            unreachable!()
2584        }
2585
2586        fn set_status(&self, _: Option<&str>, _: &mut AsyncApp) {}
2587    }
2588}